If anyone is interested, the finalists I looked into were Traveler's, Safeco, and Ace. (Ace was suggested by the Anchor Marine brokers.) I also passively looked at Progressive because USAA covers boats through them, but didn't really consider, since fees are higher even with the discounts and because of poor customer reviews.
All three offered better coverage (same agreed value for boat, boating liability, higher medical payments per person per accident, and higher commercial or on-water assistance coverage AND included coverage for my trailer) for less than my current BoatUS contract. BoatUS offers trailer protection too, but I opted out of it 2 years ago due to the extra cost. The only negatives against these companies vs BoatUS is that they don't have the same fuel/spill liability coverage and only Progressive also offers diminishing deductibles. Funny thing is, even with the greater coverage, ALL of them offered lower overall premiums than my current, less covered BoatUS insurance after deductibles.
Deductibles were slightly higher, but marginally so, especially when considering the two types of higher coverage. Agents were easy to reach and were able to talk shop and nuances without reciting a company spiel repeatedly. (My Q&A sessions with them, separate from giving them info, were usually 40 min to an hour.) At the end, I was able to lock in one of these contracts with SafeCo for about $100 less than the new Geico/BoatUS contract wanted. Ace was a decent second place. Travelers was comparable to Geico in price, but only because they offered more coverage protection and included my trailer. I will also point out that there was no waiting to talk to an agent for those 3, but I was on hold for over 15 minutes before I could even reach a Geico rep to tell them I would not be renewing my policy.
***I need to clarify deductibles being slightly higher. The deductibles I have to pay now are the same or less than the ones I originally had with BoatUS. The only reason BoatUS had lower deductibles NOW is because after 2 years of being claims free, I had gotten my deductible lowered by 50%.
Sorry my picture is not as beautiful as Spoils of War, but this was my mailer:
