I use Old United (
www.oldunited.com ) I've used them for the last 5 years or so but do not have any claim info to share. I pay just under 400 per year which is up from 250 per year because I now live in South Carolina and will get salty. I used progressive for a while but they did not cover Oklahoma when I moved from Florida a few years ago. The prices where about the same but progressive had a 10-15 percent a year discount for no claims (not sure if they still do this). I remember progressive having a retail value replacement coverage which always made me feel comfortable in case there was a total loss and I needed a new boat.
This is for an '03 190Bay with an '03 115 Johnson 4S. The insured value is just under 15k with a deductible of $500. Hope this helps.