GWX Time Compression Guidance + Buoyancy

[btaft]

I have started to play around with GWX and have been very impressed with the level of detail placed in it. I do have a couple of questions though.

1) What would be the max recommended guidline for running time compression. I am mainly concerned about having an aircraft or destroyer suddenly appear right on top of me without having any opportunity to take evasive action or dive. I plan to use the 16K mod to have a wider overall view

2) The manual states that they now give the u-boats a slight overall buoyancy and suggests that in order to maintain depth that you need to travel at at least 2kts (slower results in a depth of about 1m higher than expected). If there is a slight overall positive buoyancy does this mean that I would effectively surface (a little bit) if I am at a dead stop, or does the game artificially model this by the 1m offset

Any insight is appreciated.

Regards,

BT