Starter hanging

WOW! This thread exploded. Well, I have found the problem. Seemed to have been a couple of things I believe. First, upgraded to 1/0 battery cables. While chasing and testing the start wire from the solenoid back to the dash I noticed something that didn't look right. It seems the PO had reinstalled some wires incorrectly when he installed a depth finder. The main feed, large gauge wire was going directly into the blower fuse and then all other accesories were jumped off of that, including the ingnition switch. This would explain a drop in voltage at the start wire back to the solenoid, it would never be able to send full votage since the ignition switch was jumped with a small gauge wire. I was pissed and happy at the same time. I moved the large gauge feed to the ignition fuse and re-wired the accessories. Made sure all were contacting securely and tested. No more problems. It definitely sounds different and there is no longer a dramatic "clicking" noise when the starter engages. I did several lake tests over the weekend simulating circumstances that I had known would cause this problem before. No problems what so ever. Thank you all for the help. I have definitely learned a lot from this and to be honest enjoyed troubleshooting this problem. It was frustrating initially, but using the suggestions offered here gave me a purpose when looking for the problem. Before I was randomly searching for problems.   

p.s. Prior to the re-wire, I used a digital multimeter to test the start wire from the solenoid to the dash. It was barely 12 volts when cold and would drop to under 12 when the engine had warmed up or I had any accessories on, which would explain the intermittent issue.