what type of engine, drive, and prop, what was the boat doing before the problem started? what are the rpms at 5mph? we can help just need some information
Rickself row faster......wait for more wind..... whip the slaves more
seriously, please read what you posted. now put yourself in our shoes. how can we help you if you give us absolutely zero information?
since you posted in the mercruiser section, we can assume that you may have an I/O and it may be a Mercruiser. beyond that. what are you working on? what year? new to you boat or one you had for a while? new problem?
From your discription, it's probably the whatchama call it under the thingamajig. If you pinch off the whosit and pressurized the baggit you will pick up some speed. But if your dragit is in the water all bets are off .
Rickself Can you come back and give a little more information. All we know is that you have a slow Mercruiser. This is not enough to make any intelligent responses as you can tell by the humorous replies.