If you own a smaller boat such as a canoe or small sail/power boat, you can often purchase limited coverage for property damage through your homeowners or renters insurance policy, although liability coverage is typically not included but can often be added by endorsement.
Larger Boats like yachts or personal watercraft like jet skis and wave runners will require a separate boat insurance policy. There are generally two types of boat insurance policies.
An Actual Cash Value policy will pay for replacement costs minus depreciation at the time of loss.
An Agreed Amount Value policy means you and the insurer have agreed on the value of your boat and in the event it is totaled, you will be paid that amount.
If you have special equipment on the boat such as fishing gear or wake boards, be sure to ask your agent to see if these are covered under your boat insurance policy.