After a good few months of tinkering to get my old ww2 Darnell T class sub working,
I managed to get it all done running really well, all was going really good.
I brought it in for a check of the the watertight container as the watertight membrane had been renewed.
on top of the main perspex lid I had a screw cap for quick inspections and to access the switches. checked everything
all good watertight...perfect! I put it back in the water and took it out started the dive its going down nice and level..
then a voice behind says.... whats this cap from??
look at it and realise what I never did, look back at the sub as the casing goes below the water and then drops sharply out of sight,
followed by an air bubble popping up.
I managed wade out and get it back, took a while to dry everything out and new bits required