The trimming, foaming and ballasting was going mostly to plan, except for a problem with the acrylic water tank, which has sprung another leak. A crack has appeared again, at the join with the turned nylon end cap. This, I think, is due to the end caps being fractionally too big, putting strain on the 3mm acrylic tube. Not helped when the tube is pressurized when full of water. This is an issue, as I rely on not losing any air pressure from within this tube for surfacing actions. I epoxied and bandaged this joint as a quick fix, knowing the test tank would be gone by the end of the day.
Back to the water and the sub settled slowly down as the compartments filled up with water. The latest foam placement had cured the trim issues, with the boat settling on an even keel. Suddenly, the model started to settle rapidly, with many bubbles emerging from the rear compartment. It took about three seconds to comprehend the model was sinking!
Out of the water and back inside double quick, I already knew what had happened, I had left the aft screw cap off the model. The screw cap being directly over my Microgyros Auto Leveller, 7 Channel Futaba Receiver, Microgyros Speed Control, three Futaba Servos, two Pitmann Motors and a 9.6v NiMh pack, so no panic then!!!
Its funny, when in a workshop environment, as opposed to a salt water lake based environment, I had 30 seconds of 'what do I do'! Unscrew the big lid, got to be three minutes to do that. Nope, grab the sub, turn it upside down and pour the water down my leg!
With the test tank due to be gone within a couple of hours, I had to make a decision. So, once the water had been removed from everything, bolt it shut again and continue with the ballasting.