Abstract: An underwater sampler has a tubular body having closures biased to move from open to closed positions. The closures releasably may be latched in their open position by a latch mechanism having retainers separably coupled to anchor cables attached to the respective closures. The latch mechanism may be actuated by a weighted messenger or by a sharp tug on a hoist line by which the tubular body is suspended at a predetermined level in a body of water from which a sample is to be taken.

Abstract: A plankton sampler comprises a gathering net coupled to and in communication with a container having an inlet at one end and an outlet in its side through which water may flow outwardly of the container. Removably accommodated in the container is a screened sample collector, the screen of which is of such size in relation to that of the container that an annular space is provided between the collector screen and the inner surface of the container, thereby enabling water to flow outwardly from the collector into the annular space and thence through the opening in the side of the container.

Abstract: A Kemmerer style water sampler has a tubular body open at both ends and through which a connecting rod extends. One end of the connecting rod is fixed to a lower closure and has a latch mechanism at its other end coupled to an upper closure. The latch mechanism is releasable by means of an actuator which is movable in response to the application thereon of a tensile force in a direction to release the latch and enable the closures to move to body sealing positions. The tensile force may be applied on the actuator in virtually any position of the tubular body.

Abstract: Sampling apparatus for taking underwater samples has an open ended tube fitted with closures biased for movement from positions in which the ends of the tube are open to a position in which the ends of the tube are closed. A releasable latch releasably maintains the closures in their open positions. A latch release line is coupled to the latch for transmitting to the latch from a remote point a tensile force of such magnitude as to release the latch. An elastic connector acts on the closures in response to release of the latch to move the closures to their closed positions.

Abstract: A benthic dredge has a hollow body provided with closures at its upper and lower ends which are movable between open and closed positions. The closure at the lower end of the body is in the form of clamshell jaws which are pivotable about an axis located between the upper and lower ends of the body. Movements of the jaws are controlled by vertically reciprocable operating members and a force transmitting toggle linkage. No part of the linkage extends at any time beyond the confines of the body and the linkage is of such construction as to be capable of applying substantial closing force on the jaws as they approach their closed position.

Abstract: A reversing thermometer frame adapted to be clamped to a water sampler and lowered to a predetermined depth in a body of water. The frame has a base coupled to a case containing one or more of the reversing thermometers. The thermometer case is rotatable through about 180.degree. and is biased by a torsion spring reacting between the case and the biase for rotation from a first position to a second position. A releasable latch reacts between the base and the case to latch the latter in its first position against the bias of the spring. The thermometer case is open at one end for the insertion and removal of thermometers. At the open end of the case is a closure that is linearly and rotatably movable relative to the case so as selectively to close and open the open end of the case. The connection between the case and the closure is such that the latter must move linearly a predetermined distance relative to the case before it can be rotated, thereby preventing inadvertent loss of the thermometers.

Abstract: Apparatus for separably coupling one end of a sample container to an open end of a sample gathering net comprises an annular body adapted to be secured to the one end of the container and removably telescoped within the open end of the net. An elastomeric retainer encircles the end of the net and the body member and is accommodated in an annular groove formed in the body member. An annular anchor member encircles the elastomeric retainer and applies a radially compressive force on the latter to clamp the open end of the net in the groove of the body member. The anchor member has an annular groove in which the retainer seats to latch the body and anchor members together, the groove in the anchor member being of less depth than that of the groove in the body member.

Abstract: A Kemmerer style water sampler has a tubular body open at both ends and through which extends a connecting rod. The lower end of the connecting rod is fixed to a closure for the lower end of the body. The upper end of the connecting rod is releasably latched to an upper closure and carries a latch member which is engageable by and disengageable from a pair of clasp members mounted on the upper closure for movements in directions into and out of latching position. Each clasp member is provided with an upstanding motion transmitting member having inclined, confronting surfaces spaced apart to provide a chamber. Reciprocably accommodated in the chamber is an operating member that is tapered complementally to the inclination of the surfaces of the motion transmitting members so that movement of the operating member axially in one direction effects movement of the clasp members out of latching engagement with the latch member, thereby enabling the upper and lower closures to seal the opposite ends of the body.

Abstract: Releasable latching apparatus for a benthic dredge having closures latchable in open position, the apparatus comprising vertically displaceable latch pins coupled to a plunger which is vertically displaceable by a weighted messenger.