For hosts: All hosts must have standard home liability insurance if they welcome any guests on their property, not just Boondockers Welcome guests. No additional insurance should be necessary to be a host.
However, we do offer our Boondockers Welcome Protection Program at no additional charge to hosts. The Boondockers Welcome Protection Program provides liability coverage for up to US $1,000,000 per occurrence in the event of a third-party claim for bodily injury or property damage related to a Boondockers stay that is not covered by your Home Insurance Policy that you, as a Boondockers Welcome Host, must hold. This coverage is subject to an overall aggregate cap, and certain conditions, limitations, and exclusions may apply. You can read more information about this program here.
For guests: Your standard vehicle liability insurance should cover you if you somehow damage a host property with your vehicle. If you do damage other than with a vehicle, typically a home insurance policy would cover you for liability both at home and away from home, but you should check with your broker to know the exact details of your coverage.