This is an insurance policy that covers you as the owner of the vessel or anyone in charge of the Vessel with your consent for costs that you are legally liable to pay resulting from damage to any other Vessel or property or death or injury to others.
Third Party Only Insurance is sometimes referred to as Basic Boat Liability. It is important to know that Third Party Only Insurance or Basic Boat Liability do not cover damage to your own boat. If you want this covered you’ll need a quotation for comprehensive insurance.
It is worth considering in that worst case scenario that your boat sinks you should also consider that you’d be responsible for the removal and potentially the clean up costs as well.