Help finding unusual liability coverage

I rent a storage unit is California. The owner has changed his insurance coverage and now requrires all tennents to carry a $1M liability policy. I have not found it possible to find such coverage. Here are the relevant details:

While I am officially a Florida resident, I live on a sailboat with no fixed location. The sailboat is insured for international travel, which it does, and the covering company does not offer any kind of liability coverage like this. Additionally complicated because my partner is the owner of record, so her name is on the policy.

Right now, the storage unit is the only "land based" property I own. There is no fixed address that a standard renter's policy needs.

There is no need for coverage of the goods in storage, I can afford that loss, but I would be happy to pay for that if it got me the liability coverage.

Some storage units DO seel this kind of coverage, but apparently only to their tennants. This is a small private building, and they don't offer that.

Ideas?