An upgrade to the boat found here >>1823492
A noted upgrade to the small launch used by Pressure Cooker — It's now also an airship.
The actual modifications are minor and can be reworked as required. They consist primarily of a wooden propeller which can be disassembled and easily stored, mounted onto the back of the vessel. It's driven by a chain linkage to the prop shaft within the cabin, while the balloon itself is filled by a mixture of P-235 and helium and inserted via a tank within the cabin itself. The control line leads from a hole in the roof to the balloon in question meaning the pilot can quickly adjust the pressure within it.
The rudder control cables enter through a similar slot to the pipe, while a heat deflector prevents the heat generated by the smokestack causing problems for the balloon. The balloon itself is entirely inflatable save for the rudder and access hatch, and sports an impressive internal volume in the inner P-235 chamber that's easily two ponies tall, when the outer chamber is inflated. To ensure an even filling of P-235, the inner chamber has six flexible vents running from the input hose along the bottom of the chamber.