I am having the exact same problem with my Sea Ray 185. I was crusing on the lake and the boat went dead. I checked the fuse box and the ignition fuse was blown. I put another one and as soon as I tried to start the same issue happened. I looked all over for a short circuit or any messed up cable but could not find anything. the boat has less than a year and I have not done anything to it... like adding a new radio or any electrical thing. I will try to take to the dealer but they may take some time to fix it since there is a big waiting list...

I have been looking all over for a troubleshooting guide.. any ideas?