This weekend my boat began spewing water from under the dash and it seems like my water pressure is to high. At 4000 rpms my gauge pegs out at 15 psi. Any help would be greatly appreciated.

It pegs at 15# thats where I want mine running at 4-5K sounds to me like your hose is busted at back of gauge or gauge busted. If it has been outside and froze with water in gauge it froze and busted it. You can get a new gauge with tubing at Bass Pro for around $55 i just bought one to replace mine with it goes to 30psi I think.

Ok thank you much i will try replacing the gauge and hose.

Etex is correct. Replace the gauge. When I use to keep my old boat outside, I had to replace it three times. If you get tired of doing in the future, just take the gauge off the boat after you use it during your winter outtings and shake all the water out of it. It only takes a few drops inside to freeze and then ruin the gauge.