Abstract: A submersible electronics device for use in a body of water and a substratum floor below the body of water includes a submersible housing, an operational electronics system, and a mobility system. The operational electronics system is mounted in and/or on the housing. The operational electronics system is adapted to communicate with another device and/or to sense at least one of a physical signal and an environmental parameter. The mobility system is selectively operable to fluidize the substratum, vibrate the housing, and/or adjust a buoyancy of the submersible electronics device to selectively move the housing into the substratum to at least partially bury the housing in the substratum and/or to selectively move the housing out of the substratum to at least partially unbury the housing from the substratum.

Abstract: An unmanned underwater vehicle for use in water and with at least one acoustic signal source includes a vehicle body, a steering mechanism to direct the vehicle body through the water, a propulsion device to force the vehicle body through the water, and an adaptive Doppler guidance and control (ADGC) system. The ADGC system is configured to receive acoustic signals from the at least one acoustic signal source and to control the steering mechanism using changes in at least one frequency component of the received acoustic signals caused by Doppler shifts.

Abstract: A water submersible communications device for use on a body of water includes a housing and a communications module. The housing has a geometric centroid. The housing is submersible in and floatable on the body of water. The communications module is mounted on and/or in the housing. A center of buoyancy of the communications device is located substantially at the geometric centroid of the housing.

Abstract: Devices for navigating in a fluid medium having a solid boundary include a vehicle body and a fin attached to the vehicle body. The fin is configured to oscillate relative to the body such that interaction between the fin and the fluid medium produces propulsive forces that propel the vehicle body in a desired direction in the fluid medium. The fin is also configured to rotate relative to the body along a transverse axis such that engagement between the fin and the solid boundary propels the vehicle body in a desired direction on the solid boundary.

Abstract: Devices for navigating in a fluid medium having a solid boundary include a vehicle body and a fin attached to the vehicle body. The fin is configured to oscillate relative to the body such that interaction between the fin and the fluid medium produces propulsive forces that propel the vehicle body in a desired direction in the fluid medium. The fin is also configured to rotate relative to the body along a transverse axis such that engagement between the fin and the solid boundary propels the vehicle body in a desired direction on the solid boundary.

Abstract: Devices for navigating in a fluid medium having a solid boundary include a vehicle body and a fin attached to the vehicle body. The fin is configured to oscillate relative to the body such that interaction between the fin and the fluid medium produces propulsive forces that propel the vehicle body in a desired direction in the fluid medium. The fin is also configured to rotate relative to the body along a transverse axis such that engagement between the fin and the solid boundary propels the vehicle body in a desired direction on the solid boundary.