Patience.... Probably just need to bleed the air out of the lines. Does you pump pressure switch turn the get satisfied or is the pump on all the time when you turn-on the circuit breaker? Hopefully not, but not to worry yet.
Assuming that your boat doesn't have some odd plumbing; I'd close all the faucets. Then open the "farthest" away hot water faucets a little bit so that you allow a little flow out. It should bleed-out air and water. After a bit, you can open the water on that hot water faucet more. When it stop belching. close it down to just a "trickle", go down the line and repeat with each hot water, faucet.
Then turn-off all of the hot water faucets. Hopefully, you're pump will turn-off. Now try the same approach with all of the cold-water faucets.
Then go to farthest hot water faucet; and, open it only. You will hopefully be done. It may relieve a bubble or so. but it should better. Then try the cold water.
If you have a cockpit shower (or a anchor wash down w/ fresh water, which I doubt) make sure you include them in your procedure.
Did you blow down the water system to winterize the fresh water system? Did you run the tanks "DRY"?
From now on during the season, try to avoid draining the tanks. When they're empty. Just stop and change tanks (if you have that option) or can avoid trying to get "water from a rock" ;^)))).
If that doesn't work, then we can start doing other things while you troubleshoot things.
