[Sailor Steve]

Part of the problem of SH3 and its successors is that they had to make them workable with low-powered computers. A wind speed of 7 m/s is about 12 knots an will produce a wave height of about two meters, or seven feet. Waves of that height will be washing over the the u-boat's deck and making it pretty hard to keep your balance while loading a gun. The stock game doesn't show that. At 7 m/s the sea in the game looks flat calm.

One way to overcome that is to use SH3 Commander and set the wave height to 'Double' or to 'Seasonal'. Then you can see the effects of the waves much more clearly.

Another way is to use GWX. That supermod allows you to operate the gun in wind speeds of 11 m/s. You can set the 'Storm Conditions' yourself within the game, but most people don't want to get that involved with the workings of the game. Another problem is that the crew's wet-weather gear is also tied to the 'Storm Conditions' setting. Set it so you can use the guns in 15 m/s winds and they'll never put on their storm gear.

As for the watch crew going below, it's for their own protection. When the guns are in use there is a chance that someone might be shooting back. This is especially true of the AA guns. A watchman is useful for nothing more than getting shot when planes are about.

I don't know if there's a mod for that one or not.