full static diving with a SD

[roedj]

Bob,

In your newest newsletter you said:

This means that full static diving is not possible, but if you want to be able to pull that parlour trick out of your hat, the option will be available to purchase the snorkel and safety valve components to convert to full SAS static diving!

I have long admired the work of DM and his WTCs but have also regarded them as being very capable ways to build a dynamic diving sub and not full static diving in that with DM's design some - not much, mind you,but some - forward motion is required to fully submerge to overcome the positive buoyancy built in if you choose to build it like that.

Just so we're on the same page here, I define a fully static diving system as being able to submerge and surface without any forward motion.

Please explain your newsletter statement and how it is achieved.

Thanks for your time and patience,

Captain Confused

[roedj]

David,

Thanks for your reply. This may be case where my mileage varies.

You seem to be saying that one can achieve the static dive by adjusting the amount of ballast/water on the fly to obtain that mythical neutral point. I'm assuming that one takes on more ballast water by opening some valve to allow air to escape and water enters the ballast tank. To lessen the water ballast one may pump scavenged air in from the dry sections of the WTC OR use the Propel to blow water out.. Going back and forth between these two steps - water in, water out - one can regulate the neutral point and thus the depth of the sub. If that blows your blouse - go for it (pun intended).

The problem is - and this may well be only a problem in my over analytical head - that one is constantly dealing with a main ballast tank that is neither totally full nor totally empty - a state that you yourself have rightfully preached against. If you're running in a pool or shallow clear water this is probably no big deal. If the boat goes to the bottom it's easily retrieved. But, and for me it's a big BUT because I sometimes run in very deep water, I would rather just set up the boat to be slightly positively buoyant, have a Propel/ compressed air backup system and try not to do anything massively stupid. But then again I also have at my disposal a OTW ballast system that I got from Bob, in which outside water cannot have a pressure effect on ballast water already in the ballast tank because of a shut-off valve.

And for what it's worth, I truly appreciate you taking your valuable time to answer my questions.

Captain Contented

[roedj]

David,

Thank you for that clarification. It helps to bring our mileages into a closer alignment.

Captain Contented