Mast system and method

A mast system for use with an underwater vehicle, comprising:

• a support base defining a base axis;
• a mast arm defining a longitudinal axis, and comprising a free longitudinal mast end and a mast mounting portion longitudinally spaced from said mast end;
• a payload bay provided at said mast end, configured for supporting a payload therein;
• a pressure vessel comprising a payload housing fixedly mounted to said mast mounting portion, the payload housing including a chamber with a chamber opening configured to allow the payload bay to be selectively retracted into and selectively extracted from the payload housing;
• the mast arm being mounted to the support base via said mast mounting portion, and the mast arm being selectively deployable with respect to the support base at least between a retracted configuration, in which said mast end is at a first spacing with respect to said mast mounting portion, and an extended configuration, in which said mast end is at a second spacing with respect to said mast mounting portion, wherein said second spacing is greater than said first spacing,
• wherein the pressure vessel prevents fluid communication and pressure communication between the payload bay and an outside of the mast system in a housed configuration concurrent with the mast arm being in the retracted configuration,
• wherein said mast arm is pivotably mounted to said support base about a pivot axis via said mast mounting portion, said pivot axis being orthogonal to said longitudinal axis,
• wherein said mast arm and said payload housing together are reversibly pivotably movable with respect to said support base about said pivot axis between a stowed position and a deployed position.