I like Harbour insurance. We used them for our trailerable boats and now our keel boat. They have offices in Toronto and Vancouver. We had a claim on our boat and they were on it quickly, authorized the repair in days, no problems. I've found them good to deal with.
We originally had Skippers Plan out of Toronto on our first trailerable boat. When we asked about taking it to the Florida Keys one winter they had a fit. I just cancelled and found another company.
The important thing is liability insurance, if you have a fuel spill, or someone gets hurt etc. a million does not go far.
Many household policies will cover a boat under 26'. Some will exclude them if you can cook on board. Make sure the agent knows the rules.
Good luck, Bob