Abstract: A hydraulic lock of a tiller-based watercraft steering system is responsive to tiller release to lock a watercraft's steered element in the last commanded position upon tiller release. The hydraulic lock can be controlled through an actuator assembly that is provided between a tiller arm and the watercraft's steered element. One or more cables connect the actuator assembly to other components of the hydraulic lock. A thermal compensator regulates pressure within the hydraulic lock by accommodating changes in temperature related characteristics of the fluid within the hydraulic lock Increases in fluid pressure due to thermal expansion can be mitigated within the thermal compensator by automatically or manually directing a volume of fluid from the hydraulic lock, through a compensating valve assembly, and into a reservoir. Decreases in fluid pressure can be mitigated by directing fluid from the reservoir back into the hydraulic lock.

Abstract: An ice brake is presented that provides stopping traction on ice, snow, water, dirt, gravel, and solid ground. It is driven by a hydraulic ram to provide quick response. The brake has a blade with a bottom edge that has cutout portions to allow up to 50% debris accumulated by the brake to escape. This increases drag, because debris is forced to pass through these cutout sections. The brake is strong enough to apply sufficient loading force on ice to break a craft's hull free from being frozen down to ice, yet it is flexible enough to bend out of the way of rocks and other immovable objects.

Abstract: A bottom structure of a personal watercraft enhances the running performance of a personal watercraft. A concavo-convex face (21) having very small concave or convex portions for drawing air from an outside of a watercraft is formed on a water contact face (S) in a bottom surface (20) of the personal watercraft during planing. The air is drawn by the concavo-convex face (21), thereby separating a water flow from the bottom surface (20). Consequently, frictional resistance to the water in the bottom surface (20) can be reduced.