Motorized equipment sits outside the policy
Boats, personal watercraft, RVs and anything with an engine are excluded or severely limited on a homeowners form, whether they are on the water or on the drive. The house covers the house. Everything in the driveway generally needs its own policy, and owners routinely assume the opposite.
Trailers and gear are a middle case
An unpowered trailer may fall under other structures or personal property depending on the form, usually at a modest limit. Gear stored in it, or in a detached garage, is covered at a reduced off-premises or other-structures figure rather than the full contents limit.
Liability follows the equipment, not the address
An injury caused by a boat or a recreational vehicle is generally outside homeowners liability regardless of where it happened. That means the most dangerous things a household owns are the ones the household policy is least willing to stand behind.