Elecrical Issue...I think


So there I was driving the boat..Ran up on an shoal and killed the engine. Went to restart but only had 10.5 volts to starting battery. Called a friend who brought a jumper box. Got the battery jumped and engine cranked. But now al my gauges are pegged out. I can turn engine off but turn the key and all gauges peg to the right. Ive looked for grounding issues and cleaned the battery terminals but just cant find the issue. Any suggestions or knowledge is welcome
So there I was...

All good stories start this way!

Does it crank now (after running home) without a jump? First check battery, is it at 12 volts measured at the terminals? Will it take a charge? Wouldn't be the first battery to "just fail".

Beyond that we are gonna need more details on your setup to help troubleshoot. What engine? Carbureted or fuel injected? Standard analog gauges or some type of digital system?
I had this happen one time. Turned out that one cell in the battery shorted out and wreaked havoc on the gauges. My gauges were all electrical with sending units. I was told it was something to do with the gauges seeing a short from the battery. I put a new battery in and all was well. Not sure if you have the sam problem or not.