Don Cleavin – Using just batteries and air

You’re exercising with surface ships and occasionally the exercise demands that you don’t even start until your battery is down about two thirds of charge, so you’ve got to try and operate against opposition with a depleted battery and also depleted compressed air as well, so you’re trying to charge your battery, you’re trying to charge your compressed air groups while someone is looking for you (laughs).

Very traumatic, it can be. You just get your engines running and a Shackleton comes over the horizon.

You stop snorting and you’ve got to go deep so you’ve lost battery charging time, you’ve lost some compressed air as well. Then when it comes clear you’ve got to start up again which is quite a business to start snorting.

Simon: Why is that?

It’s knackering. There are so many tasks and things you’ve got to prepare to get the engines to run.

Dashing round to get your engines started again and hopefully you can snort long enough to recoup your compressed air and your battery power.

Simon: And the compressed air is for …

Ballast tanks. Everything you’ve got in the boat, you’ve got air to start your engines, you ‘ve got air to operate your tanks, freshwater tanks.

You’ve got to use compressed air to get the water out of your freshwater tanks.