This is our one-atmosphere dry sub that we designed and built. Last used in 1996, we stored it carefully. The hull is in excellent shape. Sacrificial anodes did their job well, preventing the hull's steel from corroding. Vast improvements in battery and engine technology make this vessel ideal for a refit. Recently we have removed all interior components and the exterior ballast tank system. A new ballast tank system will be built using an impact resistant Kevlar/fiberglass reinforced composite and upgraded components.
The hull was built with a 3/8" inch thick steel and the conning towers are 1/2" thick. Very heavy duty ribbing makes this sub stronger than the hulls of most submarines of similar size. The pressure hull's weak points are the domes, which are designed for 250-300 feet, with a 4:1 safety margin. Testing would have to be done before going deeper.
In the 1990's, electric motors were much weaker and bulkier. This sub operated with a total of 80 lbs. of thrust. This was barely adequate with modest currents and 4,200 lbs of weight to push around. New engines will provide 212 lbs. of total thrust, which will be more than adequate.
The upgraded sub will allow us to explore deeper and longer than with our fugusubs. We may use it for eco-tourism and/or the television industry.