OK, forget about the blistering. The issue is the marine growth that will develop. You'll go slower and slower and it'll be a stinky mess and hard to clean come Fall. If you pull the boat out weekly and clean the bottom then you'll be OK. But then again, that's more work than trailering.
Personally I find trailering the easy way. I have an all roller trailer so my back isn't strained. Back her in the garage and she's ready to go next week. Gas on the highway is cheaper and you don't need gas cans.
Keep her in a slip and the trouble of taking all the stuff out and putting it back in is a PITA. Just putting the cover on in the water is more than I'm willing to do.
To each his own...
Funny how folks have such a difference of opinions. I'm really with JimS123 here. I kept a boat in a slip for a while, thought we would use it more...and did in the beginning, but as mentioned, carrying coolers, chairs, towels, change of clothes, knee boards, skiis, vests, fuel, really took the convenience out of it ( very laborious IMO ), carrying the stuff 200 to 300 feet each way. It was so much easier to load the boat up at home....and unload the boat at home. Then we ended up paying about $.75 per gallon more at the dock because we got tired of carrying fuel to the boat. And even tho the slip was covered, we covered our boat with the boat cover and that was a very big chore, walkway on one side, water on the other side of the boat.. After a while, I lost 4 to 5 miles per hour on the boat top end...and that was it. I put the $90 per month slip fee back in my pocket, trailer ed from then on. But in the end, its up to you....the slips are full of boats, so there must be many good reasons for that....just not many that I could see for me....LOL