A damper is disposed between an outer peripheral surface of a bushing and an inner peripheral surface of an inner hub. The damper includes a first portion facing a rib of the bushing, a second portion facing a rib of the inner hub, and a connection portion by which the first portion and the second portion are connected to each other. In a state in which a rotational force has not been applied between the bushing and the inner hub, the damper includes a cross-sectional shape that defines a deformation-absorbing space positioned between the first portion and the second portion. The deformation-absorbing space is deformed such that the first portion approaches the second portion in a state in which the rib of the bushing and the rib of the inner hub have moved relatively by application of a rotational force between the bushing and the inner hub.

Described herein are examples of stiffening shafts, which in some cases are adapted to couple to a marine vessel. An exemplary stiffening shaft can be used to extend a motor from the marine vessel or be used as a shallow water stick anchor. The exemplary stiffening shafts can include a plurality of linked vertebrae stacked to form a column and at least one inelastic tension element threaded longitudinally through the plurality of vertebrae. The shaft can have a flexible configuration when the at least one tension element is released and a stiffened linear configuration when the tension element is tensed to react to torque and bending moments. Alternatively, the stiffening shaft can be used as a shallow water stick anchor for a marine vessel by piercing the bottom of a marine environment (e.g., a sea bed, a lake bed, a river bed, etc.).

A damper is disposed between an outer peripheral surface of a bushing and an inner peripheral surface of an inner hub. The damper includes a first portion facing a rib of the bushing, a second portion facing a rib of the inner hub, and a connection portion by which the first portion and the second portion are connected to each other. In a state in which a rotational force has not been applied between the bushing and the inner hub, the damper includes a cross-sectional shape that defines a deformation-absorbing space positioned between the first portion and the second portion. The deformation-absorbing space is deformed such that the first portion approaches the second portion in a state in which the rib of the bushing and the rib of the inner hub have moved relatively by application of a rotational force between the bushing and the inner hub.

A damper is disposed between an outer peripheral surface of a bushing and an inner peripheral surface of an inner hub. The damper includes a first portion facing a rib of the bushing, a second portion facing a rib of the inner hub, and a connection portion by which the first portion and the second portion are connected to each other. In a state in which a rotational force has not been applied between the bushing and the inner hub, the damper includes a cross-sectional shape that defines a deformation-absorbing space positioned between the first portion and the second portion. The deformation-absorbing space is deformed such that the first portion approaches the second portion in a state in which the rib of the bushing and the rib of the inner hub have moved relatively by application of a rotational force between the bushing and the inner hub.

Described herein are examples of stiffening shafts, which in some cases are adapted to couple to a marine vessel. An exemplary stiffening shaft can be used to extend a motor from the marine vessel or be used as a shallow water stick anchor. The exemplary stiffening shafts can include a plurality of linked vertebrae stacked to form a column and at least one inelastic tension element threaded longitudinally through the plurality of vertebrae. The shaft can have a flexible configuration when the at least one tension element is released and a stiffened linear configuration when the tension element is tensed to react to torque and bending moments. Alternatively, the stiffening shaft can be used as a shallow water stick anchor for a marine vessel by piercing the bottom of a marine environment (e.g., a sea bed, a lake bed, a river bed, etc.).