Homeowners liability covers only some boats. A larger boat, such as a large inboard powerboat, can fall outside Section II, which would leave the owner with no liability protection for it.

The watercraft endorsement extends Section II, meaning personal liability and medical payments to others, to a boat the base policy would exclude. If the insured strikes a swimmer while cruising, the swimmer's injury claim is covered.

What the endorsement does not do: it does not insure the boat itself. Damage to the insured's own hull needs separate physical damage coverage, such as a boat policy. Liability coverage pays for harm to others, never for the insured's own property.