Obviously the longer any metal spends it the water the worse it it for it. I assume a lift is out of the question and there is no dock to tie to. If you do leave the trailer in, be prepared for it to corrode and rust more quickly, lights to wear out more quickly, and the bearings to need replacement more often. If you want to beach it without the damage I've had good luck putting a foam pool lounge under the front of the hull to protect it. Another option is to anchor the boat off shore at a depth where you can walk out to it. I think I would try to put the boat on the trailer and pull it out, put it in when you want to use it. Keep in mind that sitting in the water for prolonged periods also takes a toll on the boat. Fiberglass blisters aren't a quick, easy or cheap fix.
This would be my opinion, others may voice different ones.
I spent most of my money on booze, broads and boats. The rest I wasted. - Elmore Leonard