A bullitine I thought would be interesting.
After having run the SB-2 in 10 ft plus depths I have noticed a 2.0 mm outward buldge or warp in the rear Lexan bulkhead and a 1.0 mm outward buldge in the front one.
I believe its from going very deep and the warm air buidup in side the casing and atmospherick pressure changes along with the pressure of the water caused the bulge.
You would think it would be the oposite or implostion from the pressure. :confused:
So what I did was to instal a one way valve and fitting in the forward top of the white casing where the vedeo connection is made just adjasent there is space for a small barbed fetting,then a tube to the external one way valve mounted on the frame.
The fitting will also provide means to pressurize the casing or vacume to locate leaks that will come eventualy as the seals crack especialy if used alot in clorinated water.
This sub has alot of seals and a quick dump in a tank will locate them if the casing is fressurized just like its done with tires works every time.
It amazing that a 6 mm thick lexan cover can be warped and by having a relief valve will prevent over pressurization,the valve is in the outward flow direction from the casing.
Also watch out for hair line cracks and cracks in general ,this is normal as long as its monitored and that they dont go across the sealed sections.
periodicly remove the rear cover plate and chech it.
The deepest I have gone so far is about 16 ft.So far so good.