While on our boat this weekend we noticed that the VHF and radio kept shuting off and then would come back on. Almost like the battery was turned off then turned right back on .... Any thoughts on what may be going on?? thank you
The VHF, radio, and any other electronics (autopilot, chartplotter, etc) are pretty critical on voltage. If your batteries are getting low, the refer cycling on, starting the engine, bilge pump, or any other momentary high load will drop the voltage momentarily and cause them to cut out. If the battery voltage is good, suspect a bad (loose/dirty) ground somewhere in the system.
I agree with Ken. Also may be a short in the system. Sounds odd; but, does the on/off coincide with wave action? I say that as the wave action may cause two frayed wires or connections to swing into each other. Happened on a Capri 25 I had.
If you have an in line fuse holder, I would check that first and make sure it is tight. It could be loose and not getting power to your VHF.
kev: Sounds like you have a faulty connection. Check the ground (-) connections/crimps.
When you look at the positive (+) wiring scrutinize the connectors/crimps as well as the inline fuse (and it's holder - see my recent Mainsheet article) that might still be there. A few thoughts