Abstract: Sub-ordinate and host maritime vessels are connected to each other by a tow loop trailed by the host vessel through a capture frame which engages the sub-ordinate vessel. The capture frame acts to engage the sub-ordinate vessel in the transitional coordinate space shared jointly between the sub-ordinate and host vessels, which vessels can be either or both surface-going, submersible, and/or non-surface vessels. The capture frame possess features which allow it to disengage from the host vessel while remaining semi-related and recoverable by a linkage of one or more tensioned lines to the host vessel during the time that its tow loop is connected to the sub-ordinate vessel.

Abstract: The invention relates to a lowerable platform (1) for a water craft (10), which can be also horizontally extended and to which a float (2) is fastened that comprises a closed hollow space (43) or an open hollow space (43), a buoyancy (A) acting upon the float (2) being generated by the air volume (L). As a result, the water craft's proper weight or the payload (N) of e.g. a tender boar (27) on the lowerable platform (1) can be compensated by the buoyancy (A). A hydrodynamic design of the float (2) additionally generates a hydrodynamic buoyancy (D1) which can be varied in terms of its height in relation to the current (S) by means (4, 37, 38, 39), depending on the float (2).

Abstract: A ship has interchangeable mission modules. For example, a ship has a frame with a mission-module bay disposed therein. The bay is operable to receive a mission module having a mission-module system and an interface that facilitates the coupling between the mission-module system and the ship. As such, a plurality of different types of mission modules can be interchanged quickly and easily to provide the ship with different mission capabilities. Each mission-module is generally self-contained such that all the equipment necessary to perform the specific mission is contained within the single mission-module. Each mission-module is either a single unit or multiple units combined together to form an integrated unit. Thus, the ship is capable of transitioning from one mission to another simply by ejecting one mission module and replacing with another mission module.

Abstract: Presented is an advance naval ship's stern appendage called an LCAC (Landing Craft Air Cushion) Lander, Launcher and Lifter (L4 system) to provide for landing and launching of amphibious hovercraft and increase the delivery capacity of amphibious hovercraft by naval vessels. The stem appendage which may be retrofitted on existing vessels or fully designed into new hull forms of new ships. Included in the stem appendage are longitudinally extending cantilever wingwalls, at least one hoistable platform with a backstop fold up gate, a med-moor ramp, drainage ducts, a resistance reduction leading edge, locking pins and a transfer conveyor system for amphibious hovercraft to gain access to and from the ship's decks above the waterline, and a hoisting system for raising and lowering the hoistable platform between said cantilever wingwalls.

Abstract: A method and apparatus for cargo transfer at sea, more particularly, a flow-through vessel and related method for the at-sea and underway launching and loading of air-cushion vehicles. The vessel includes a hull having a forward end and an aft end, a continuous deck extending from the forward end to the aft end of the hull, a forward ramp attached to the continuous deck at the forward end of the hull, and an aft ramp attached to the continuous deck at the aft end of the hull. At least a portion of the continuous deck is uncovered and accessible from above the deck.

Abstract: An embodiment of a launch/recovery device for both surface and underwater vehicles includes a plurality of driven wet-traction members arranged to form a low drag (e.g., water flow-through) ramp design. The wet-traction members provide traction even when wet between the water vehicle and the launch/recovery device. As a result of utilizing driven wet-traction members, the use of conventional hoists, special capture devices such as hooks and tow lines, and personnel located within the water to attach the capture devices to the water vehicle is eliminated. The wet-traction members provide both strength and flexibility to the launch/recovery device. That is, while the wet-traction members are strong enough to support the weight of the water vehicle, they are at the same time flexible enough to deflect a distance (e.g., about 6 to 15 inches) to accommodate a soft landing of the water vehicle on the ramp, while providing recovery forces and motion.

Abstract: A launch and recovery system for use by host vessel in launching and recovering a sub-ordinate vessel includes a ramp structure that is connected to a host vessel and movable so that at least its remote or distal end can be placed in the water, preferably at the stern of the host vessel. The ramp includes interior portions thereof that can be selectively flooded to control the buoyancy of the ramp at least its distal or remote end thereof to thus effect some measure of control of the inclination of the ramp. Additionally, one or more types of flow structures can be provided that effect control of the ramp as a function of water flow through and/or across the ramp. In one form, the flow structures can take the form of one or more thru-flow passages in the ramp so that water from the forward or leading side of the ramp can pass therethrough to the rearward or trailing side thereof.

Abstract: The present invention provides an apparatus and method of a dock system for launch and recovery of a stowed boat, which is capable of launching and recovering the boat during navigation of a marine vessel at a high headway speed. The launch and recovery apparatus has a stern dock (2) for accommodating the boat (10) therein. The apparatus launches the boat outboard through a stern opening and recovers the boat from the outboard area by entry of the boat into the dock. The apparatus is provided with a conduit device (11) so that seawater surrounding the vessel is drawn through an intake port (12) and is delivered to the dock through an outlet port (13). In the dock, a backward water stream is generated, which is to be discharged outboard through the stern opening.

Abstract: A cradle is shaped to accommodate the hull of a small boat such as dinghy, personal watercraft or other type of boat. A support is mounted to a deck such a boat, pier or dock deck. The cradle is pivotally mounted to the support and can be moved to a loading position in which the cradle is generally vertical, or inclined to horizontal, and an outer portion of the cradle is at the water adjacent to the deck. The small boat is moved upon the water against the cradle. A pair of lines extend from the support and are trained through an inner portion of the cradle. The free ends of the lines are attached to the boat, and the lines are drawn toward the support, for example with a hand wheel or hand winch. The boat is pulled toward the support while remaining in a generally horizontal orientation. The boat pivots the cradle from the loading position to a generally horizontal storage position on the deck where the boat and cradle are secured by the lines.

Abstract: An embodiment of a launch/recovery device for both surface and underwater vehicles includes a plurality of driven wet-traction members arranged to form a low drag (e.g., water flow-through) ramp design. The wet-traction members provide traction even when wet between the water vehicle and the launch/recovery device. As a result of utilizing driven wet-traction members, the use of conventional hoists, special capture devices such as hooks and tow lines, and personnel located within the water to attach the capture devices to the water vehicle is eliminated. The wet-traction members provide both strength and flexibility to the launch/recovery device. That is, while the wet-traction members are strong enough to support the weight of the water vehicle, they are at the same time flexible enough to deflect a distance (e.g., about 6 to 15 inches) to accommodate a soft landing of the water vehicle on the ramp, while providing recovery forces and motion.

Abstract: A parent-child type boat having an electric power generating device, such as a fuel cell. The boat includes a parent boat and at least one child boat which is smaller than the parent boat. The parent boat is equipped with a generating device. The child boat is equipped with a battery and an electric propulsion device. When the child boat is docked with the parent boat and electrically connected thereto, power can be supplied to at least one of the battery and the electric propulsion device of the child boat from the generating device of the parent boat.

Abstract: Devices, apparatus and systems for raising and lowering watercraft such as personal watercraft, jet skis, inflatables from transoms on boats, from bulkheads and from docks, and for raising and lowering other types of vessels. A single actuator such as a fluid operated cylinder and single piston can raise and lower a cradle that supports the personal watercraft. An crank bracket can be fixably attached to a crank shaft, and an arm which supports the cradle can be fixably attached to the crank shaft. The arm can be extendable to different lengths. The cradle can include a self-leveling carriage that uses rollers to roll on a curved surface of the cradle allowing the supported watercraft to remain in a substantially level position thereon. An adjustable swivel mount can also be used to lock the cradle to the arm in a fixed orientation.

Abstract: A support assembly for loading and securing a tender including first and second subassemblies. The first assembly includes a winch assembly for positioning the tender on the support assembly and the second subassembly includes a releasable securing device. Both subassemblies include a series of pivotal shafts having rollers which help guide and support the tender into position.

Abstract: A rescue ship for a disabled vessel includes a hull which delimits an elongated dock (12) which is at least 150 m long and preferably at least 250 m long and at least 30 m wide and preferably at least 45 m wide, and including a ballasting device enabling draught modification by at least 15 m and preferably at least 20 m. The hull has two lateral hulls capable of being ballasted (14) and enclosing the dock (12), and the stem has a practically sealed door (18) which can close the rear of the dock (12). The ship further includes maneuvering elements designed to exert a thrust in one direction transverse at least to the longitudinal axis of the ship. The invention is applicable to the rescue of disabled vessels.

Abstract: The present invention provides a connecting link assembly and socket arrangement for assembling modular dock and/or deck elements into walkways, decks and drive-on docks.

Abstract: A method for outfitting a vessel such as a water ship for a particular mission includes maneuvering the vessel toward a mission module, capturing the mission module with the vessel, and coupling the mission module to the vessel. Such method allows one to interchange mission modules, and thus outfit a vessel for different missions, quickly and easily.

Abstract: The launch and recovery system provides a dive wing and drogue assembly that is towed behind a ship by cables. The dive wing imparts a downward thrust to the drogue, so that the drogue is towed underwater, placing tension on the cables. The cables become stiff due to the speed of the ship and the weight and depth of the dive wing and drogue assembly, so that the cables take on the character of rails. The boat or watercraft to be launched is placed on a sling carriage that is slidably mounted on the cables, so that the sling slides down the cables, launching the watercraft in the stable wake of the ship. The watercraft is recovered by tying a winch cable or line to the watercraft, winching the watercraft back onto the sling, and winching the sling back onto the fantail of the ship.

Abstract: A pair of spaced parallel female slots or grooves located on the bottom of a watercraft float enable the pair of spaced parallel male ribs or rails located on top of a float to fit within the slots or grooves on the bottom of another float when the watercraft floats are interconnected or stacked on top of each other.

Abstract: A submersible vehicle launch and recovery system comprises a grab comprising at least two arms capable of moving relative to each other, the arms being rotatable between an open position and a closed position, in which closed position the jaws of the arms are able to grip a handling feature on a submersible vehicle. The arms comprise attachment means so arranged that the arms tend to close when the system is suspended by the said attachment means, at least one arm comprising buoyancy means so distributed as to tend to open the said arm when the system is submerged.

Abstract: A semi-submersible offshore vessel has a substantially ring-shaped lower pontoon, starboard and port forward columns extending upwards from the lower pontoon, and starboard and port aft columns extending upwards from the lower pontoon. An upper deck structure connects upper portions of the columns with each other. The upper deck structure has a substantially rectangular module recess for receiving one or more operation modules, for example, carrying hydrocarbon-processing equipment. The upper deck structure is generally C-shaped, having a forward torsion box extending transversally between the starboard and the port forward columns of the semi-submersible offshore vessel, and two mutually parallel longitudinal side beams extending aft from the starboard and port forward columns to the starboard and port aft columns, respectively, in such a way that the module recess exhibits an open aft end, the width of which substantially corresponds to the width of an operation module.

Abstract: A davit system includes an elongate base having a straight part and a leading part that is angled downwardly relative to the straight part at a predetermined angle. An elongate boom arm is slideably disposed in a hollow interior of the elongate base. The boom arm is fully retracted within the hollow interior of the elongate base when an elongate screw is rotated in a first direction a predetermined number of times and the boom arm is fully extended from the hollow interior of the elongate base when the elongate screw is rotated in a second direction a predetermined number of times. The boom arm is downwardly angled at the predetermined angle when the boom arm is in its fully extended position. In a first embodiment, two elongate bases and boom arms are provided and each boom arm supports a cradle at its leading end for lifting a boat.

Abstract: A parallelgram arrangement of linkages interconnect a stern ramp frame with a plurality of parallel rails vertically adjusted to positions above the ramp frame by actuators for reception and maintenance of a watercraft thereon with minimized vibration, further reduced by shock-absorbing springs positioned in engagement with the rails and the rail actuators. Rail positioning adjustment by the actuators is effected under computer control to match different hull shapes of the watercraft that are curved or v-shaped and therefore non-flat.

Abstract: An auxiliary watercraft roll-on, roll-off cradle system removably attachable to an aft platform of a boat consists of a first set of rollers tiltably attached to the platform and a second set of supporting rollers removably attachable to the platform.

Abstract: Improved systems and methods for transporting fluids in containers are provided. Such improved systems and methods include floatable container vessels having one or more fluid containers and self-propelled marine transportation vessels that are adapted to be ballasted downwardly to permit the floatable container vessels to be floated onto or off of the marine transportation vessels, and are adapted to be deballasted so as to raise the floatable container vessels out of the water for transportation to another location.

Abstract: A transport, launch and recovery marine craft is provided that is capable of transporting, deploying and retrieving cargo at sea, either while idle or while underway. A hinged well deck selectively lowers the cargo into the water, and lifts the cargo out of the water during retrieval. Means for raising and lowering the well deck include hydraulic or pneumatic cylinders connected between the well deck and an overhead support. A winch may be used for loading and unloading the cargo.

Abstract: A towed raft has a generally U-shaped floating frame and a spine and rib assembly that substantially define a receiving area configured to receive a marine vessel substantially through an open end of the floating frame. At least one lifting device is mounted to said spine. The floating frame comprises a pair of floats connected by a cross brace at the forward end. The assembly comprises a spine spaced upwardly from the frame and generally longitudinally aligned with the receiving area, and a plurality of ribs extending generally outwardly and downwardly from the spine to connect the spine with the frame. The towed raft may be used for transport, launch or recovery of a marine vessel such as a swimmer delivery vehicle (SDV).

Abstract: The present invention provides an apparatus, method and system for delivery of commercial cargo containers shore side without container terminals. The present invention utilizes containers made autonomous by coupling a container with a detachable propulsion system, having a motor and navigation and steering controls, permitting the rapid, controlled, efficient and safe delivery of cargo containers individually by water. Ballast units, deployment systems and control via remote units are also disclosed. These improvements allow the containers, utilizing their inherent buoyancy, to approach a shore autonomously according to a preplanned or remote controlled route to a specific location and in a specific order of arrival, thereby reducing the number of cargo handlers required, speeding the delivery process to the shore, and eliminating the need for high-technology pier-side equipment.

Abstract: In accordance with the present invention there is provided a lifting device for a boat, the lifting device including a first platform and a plurality of linkage members, the plurality of linkage members configured to form at least two four-bar linkage assemblies, each having a first end pivotally attached to the platform and a second end pivotally attached to a boat. The lifting device further including at least one hydraulic cylinder, the cylinder having a first end and second end, the first end being pivotally affixed to the structure of a boat and the second end pivotally attached to at least one linkage member, and a fluid device in communication with the hydraulic cylinder. A load sharing member connects the two four-bar linkage assemblies and prevents uneven or tilted motion of the platform.

Abstract: A boat has a system for converting a utility space used for garaging a dinghy and formed under the cockpit of the boat into an additional living cabin when the dinghy is removed from the garage.

Abstract: A boat-lift system adapted to move a smaller boat relative to a larger boat. The boat-lift system comprises a structural support, a lift structure, a pivot system, and an actuator assembly. The structural support is adapted to be rigidly connected to a transom of the larger boat. The lift structure defines a second pivot portion, an actuator portion, an extension portion, and first and second boat-engaging portions. The pivot system connects the first and second pivot portions to allow rotation of the lift structure between first and second lift positions relative to the structural support. Actuation of the actuator assembly causes the lift structure to move between the first and second lift positions. When the smaller boat is in a docking position adjacent to the lift structure, operation of the actuator assembly moves the lift structure to lift the smaller boat from the docking position to a first storage position.

Abstract: A launch and recovery system for unmanned underwater vehicles (UUV) includes a watercraft with a stern endwall movable between a vertical position and a ramp position that is angled downward toward the water surface. A storage platform mounted on the watercraft and terminating at the stern endwall defines a storage area for UUVs. An arm is pivotally mounted to the watercraft at a position forward of the storage platform. The arm has an outboard end that can be extended to positions aft of the watercraft and on either side thereof. The arm is also retractable such that its outboard end is positionable over the storage platform. A capture mechanism is mounted to the outboard end of the arm and is used to capture a UUV that maneuvers thereto in the water. A homing mechanism is coupled to the arm and is used to transmit a homing signal through the water for use by the UUV in maneuvering towards the capture mechanism.

Abstract: An auxiliary watercraft roll-on, roll-off cradle system removably attachable to an aft platform of a boat consists of a first set of rollers tiltably attached to the platform and a second set of supporting rollers removably attachable to the platform.

Abstract: An offshore construction system comprises a work module support vessel having a ballast-down mode, in which a deck of the vessel is submerged below the water surface, and a ballast-up mode, in which the deck is disposed above the water surface. The system further comprises an independently floatable, pontoon-supported work module carried on the deck of the support vessel. The system also includes a draw connected between the work module and the work module support vessel. The draw has a draw-over mode, in which the work module is drawn over the deck of the support vessel, and a remove mode, in which the work module is removed from the deck.

Abstract: A platform topsides can be transferred from a substructure to a transporter by ballasting the transporter, locating the transporter underneath the topsides and deballasting the transporter, causing load transfer units of the transporter to lift the topsides off the substructure. Each load transfer unit comprises a compression spring which rests on a layer of particulate material located in a drum, the particulate material in turn rests on a releasable hatch-cover. The springs provide a flexible connection between the transporter and the topsides. During the deballasting of the transporter, the hatch-covers are released to suddenly let out the particulate material from the drums, thereby lowering and relieving the springs, causing a direct contact and a stiff connection between the transporter and the topsides.

Abstract: A laden ship is transported across a shallow portion of a watercourse by a submergible floating vessel, while the ship is lifted upwardly within the water by means of a vessel platform placed under the hull. The vessel is preferably comprised of a multiplicity of rigid U-shape, separately floodable, buoyant sections, including end sections, which have self-propulsion. The several sections are pivotably interconnected, as by hinge assemblies, so the transporter platforms adjust to major up or down bends along the length of the hull, during lifting. The platforms are surfaced with a layer of resilient deformable material, or movable blocks, to accommodate local irregularities in the bottom of the ship.

Abstract: A boat lift for attachment to the aft transom of a larger boat for lifting and lowering smaller water craft, utilizes a single double acting hydraulic cylinder to move a truck horizontally within an enclosure. Cables fixed to the truck cause movement of vertically disposed connectors attached to a intermediate vertically moveable members which in turn include cables attached to vertically moveable support posts which carry water craft support arms.

Abstract: The method for removing or positioning a structure (103) which is erected on either an underwater bed or anchored to the underwater bed entails the use of a hoisting mechanism. When the structure (103) is being removed, it is detached from the underwater bed. Then, the structure (103) is connected to a hoisting mechanism which is arranged on a separate hoisting vessel (100). The structure is hoisted up by the hoisting mechanism and is attached to a transport vessel (1) in such a manner that it can tilt about a horizontal axis. Then, the structure is tilted into a substantially horizontal position. The structure is positioned in the reverse order.

Abstract: The carrier includes a cradle having an elongated spine and a number of ribs which are spaced along the length of the spine. The spine is pivotally attached to a larger boat such that an end of the spine may be raised or lowered. When the end of the spine has reached its lowermost extent, it is immersed in water and allows a smaller boat to be floated into the cradle. When the end of the spine is raised to its uppermost extent, the smaller boat is lifted entirely out of water. A hoist or actuator serves to raise and lower the end.

Abstract: Improved systems and methods for transporting fluids in containers are provided. Such improved systems and methods include floatable container vessels having one or more fluid containers and self-propelled marine transportation vessels that are adapted to be ballasted downwardly to permit the floatable container vessels to be floated onto or off of the marine transportation vessels, and are adapted to be deballasted so as to raise the floatable container vessels out of the water for transportation to another location.

Abstract: A dinghy lift for mounting to a boat beneath a swim platform. The dinghy lift includes a pair of space-apart lift mechanisms that are mounted to the stern beneath the swim platform. The lift mechanisms do not extend outwardly beyond the swim platform and therefore are generally hidden from view. A pair of arm are removably mounted to the lift mechanisms. The arms extend outwardly beyond the swim platform to form a cradle for the dinghy. The lift mechanisms selectively move the arms between a lowered position for loading and unloading the dinghy and a raised position for storing the dinghy.

Abstract: A method for bringing people in life boats in the sea aboard a support vessel, in which a rescue craft is launched from a ramp in the stern of the support vessel. The rescue craft carrying a rope from a winch in front of the ramp. The rope is attached to a life boat in the sea. The life boat is hauled onto the ramp by the winch and the life boat is emptied. A support vessel for launching and recovery of rescue crafts and life boats including a stern ramp for launching and entering of rescue crafts and life boats and a winch for hauling the rescue crafts and life boats onto the ramp.

Abstract: A platform structure for a water structure surrounded by water is disclosed. The platform structure includes a set of inflatable sacks held in place by arm members which are hollow tubes rotatably attached to a hinge structure to a side of said water structure. The platform structure is especially designed to protect the water structure as well as other approaching water crafts from the impact of collisions. The arm members of the platform structure can also be used to tug floating platforms and various water crafts with minimal water drag. The platform structure can also be adjusted to function with a hinge structure installed at any of various heights on said water structure. The platform structure also has means to provide it with added stability on the water.

Abstract: A multi-use construction vessel designed to receive a variety of float-on modules that accommodate project specialty equipment and still allow the mother vessel to operate in the traditional construction mode. The vessel may be formed as a new construction or by converting an existing vessel. The vessel is provided with a lowered center section between the bow and stern. The center section is adapted to receive and secure float-on modules containing the equipment required for the desired operation. The center section may also be provided with a moon pool for laying pipeline directly through the vessel. The vessel is ballasted to position the center section below the water line so that the float-on modules may be installed or removed. The stern section of the vessel includes a derrick crane for normal construction lifts and moving pipe and equipment on the center section as necessary.

Abstract: According to a preferred embodiment, the present invention provides a wet/dry garage for the hull of a marine vessel. The garage includes a compartment defined within the hull of the marine vessel, with a floor below the vessel's waterline and a ceiling above the waterline. One side of the compartment is a door opening defined in the hull of the vessel. The door opening has a lower edge below the vessel's waterline and an upper edge above the waterline of the vessel. A door is mounted to the vessel and can be closed to cover the door opening. The compartment contains at least one small boat storage position. The door may be lowered to a position providing sufficient draft that a smaller watercraft can be propelled into or out of the compartment. Preferably the door can be closed to form a watertight seal surrounding the door opening. After closing the door, the water in the compartment is evacuated to lower the smaller watercraft into a storage position.

Abstract: A subject of the invention is a ship (20) for recovering petroleum products floating at the surface of the sea, characterized in that it comprises an open front part equipped with a rotary collecting drum (24) which is partially submerged and comprises longitudinal elements (32) that can be moved with respect to the external surface of this drum (24) between two positions, one projecting, one retracted, a hopper (40) situated behind the said drum (24) for recovering the said petroleum products removed by this drum (24), and means (45) for transferring these products from the hopper (40) to at least one settling and storage tank (46). Another subject of the invention is a mobile installation for storing and transporting petroleum products recovered by recovery ships.

Abstract: A drone vessel for an ROV. The drone vessel utilizes dynamic positioning. The drone vessel is remotely controlled by radio telemetry, preferably modular in construction, and may be semi-submersible. The vessel contains a radio telemetry package, one or more generators, an umbilical winch for lowering and raising an ROV, space for receiving and storing an ROV, and ballast control. The central compartment in the drone vessel is free flooding and houses the drum for storing umbilical line and the winch for paying out umbilical line to the ROV. The central compartment also includes space for the ROV.

Abstract: A method to transport a deck at sea and install the deck on an offshore substructure. The deck is completely fabricated on a set of deep girders. The deck and deep girders are skidded onto two pontoons. The deck and deep girders are tied down together. A set of jacking units is installed into the deep girders prior to sail out. The complete assembly is towed to the installation site. At the site, the tie downs are removed. The girders are jacked up and the pontoons simultaneously ballasted down until the assembly is supported on the pontoons.

Abstract: A transom bracket enclosing a hydraulic power cylinder is mounted to the transom of a watercraft. An actuation rod of the power cylinder moves multiple lift arms connected to a platform bracket supporting a platform for supporting a small auxiliary watercraft. Electrical or manual operation of the power cylinder causes the platform bracket to move in a vertical direction either upwards out of the water or downwards into the water. A lock mechanism operated by a lock cylinder locks the lift apparatus in place when not in operation. Grooves on sides of the transom bracket and transversely extended pins connecting the linkage arms provide a downward stop to movement of the lift apparatus.

Abstract: The carrier includes a cradle having an elongated spine and a number of ribs which are spaced along the length of the spine. The spine is pivotally attached to a larger boat such that an end of the spine may be raised or lowered. When the end of the spine has reached its lowermost extent, it is immersed in water and allows a smaller boat to be floated into the cradle. When the end of the spine is raised to its uppermost extent, the smaller boat is lifted entirely out of water. A hoist or actuator serves to raise and lower the end.

Abstract: The patent describes a power boat having a transom and a swim platform or step generally projecting from the transom at a right angle at or near the water line. The swim step is adapted to the launching of a seated rider carried on a sky ski having an elongated board and a tee bar normally extending from the board into the water. The swim platform has a slot adapted to receive tee bar and extends from the port and/or starboard margins and runs generally parallel to the transom to an extent sufficient to snugly receive the tee bar while the board is supported by the platform with the tee bar extending through the slot and below the platform into the water whereby a rider can mount the seat and secure himself to the sky ski and then readily launch himself and the ski by pushing out of the slot.