Implementations described and claimed herein provide an underwater vehicle includes a vehicle body having a frame enclosed by a fairing. The vehicle body extends between a proximal end and a distal end and defining an interior. A nose is disposed at the proximal end of the vehicle body. The nose has a tow system configured to move between a tow position and a stow position. A propulsion system is disposed at the distal end of the vehicle body. The propulsion system includes a plurality of control fins and a thruster. A power distribution system is housed in the interior of the vehicle body. The power distribution system includes a first power system housed in a first pressure vessel and a second power system housed in a second pressure vessel. The first pressure vessel is isolated from the second pressure vessel.

A composition is provided for producing a 3-D printable material comprised of a marine biodegradable base polymer and a gelling agent in a ratio preselected to achieve a desired rate of degradation of a structure printed from the material. Suitable polymers include polycaprolactone (PCL), polyhydroxyalkanoate (PHA), or polybutylene succinate (PBS). The gelling agent is typically agar. Faster rates of degradation of the structure are obtained with larger proportions of gelling agent in the composition. The composition may also include biological materials to further promote or control the biodegradation of the structure, and other additives such as nutrients for microorganisms or solidifying agents. 3-D printing of the material occurs at relatively lower temperatures to avoid damage to the biological materials.

A composition and method are provided for producing a 3-D printable material comprised of a marine biodegradable base polymer and a gelling agent in a ratio preselected to achieve a desired rate of degradation of a structure printed from the material. Suitable polymers include polycaprolactone (PCL), polyhydroxyalkanoate (PHA), or polybutylene succinate (PBS). The gelling agent is typically agar. Faster rates of degradation of the structure are obtained with larger proportions of gelling agent in the composition. The composition may also include biological materials to further promote or control the biodegradation of the structure, and other additives such as nutrients for microorganisms or solidifying agents. 3-D printing of the material occurs at relatively lower temperatures to avoid damage to the biological materials.

Implementations described and claimed herein provide an underwater vehicle includes a vehicle body having a frame enclosed by a fairing. The vehicle body extends between a proximal end and a distal end and defining an interior. A nose is disposed at the proximal end of the vehicle body. The nose has a tow system configured to move between a tow position and a stow position. A propulsion system is disposed at the distal end of the vehicle body. The propulsion system includes a plurality of control fins and a thruster. A power distribution system is housed in the interior of the vehicle body. The power distribution system includes a first power system housed in a first pressure vessel and a second power system housed in a second pressure vessel. The first pressure vessel is isolated from the second pressure vessel.

Implementations described and claimed herein provide an underwater vehicle includes a vehicle body having a frame enclosed by a fairing. The vehicle body extends between a proximal end and a distal end and defining an interior. A nose is disposed at the proximal end of the vehicle body. The nose has a tow system configured to move between a tow position and a stow position. A propulsion system is disposed at the distal end of the vehicle body. The propulsion system includes a plurality of control fins and a thruster. A power distribution system is housed in the interior of the vehicle body. The power distribution system includes a first power system housed in a first pressure vessel and a second power system housed in a second pressure vessel. The first pressure vessel is isolated from the second pressure vessel.

Methods, systems and apparatuses are disclosed for joining assemblies, particularly joints and joining assemblies for co-joining composite components and metal components in a joining assembly, and inhibiting corrosion of metal components secured to composite component via a joining assembly.