Renter's Insurance for USA aircraft hire

[prate]

I've done a search but can't find exactly what I'm looking for, so hoping someone who has rented recently in the USA might be able to answer my question.

I've found AOPA and Avemco for renter's insurance but both only offer annual policies. I'm looking for a policy for a short duration - only need it for about a week. Has anyone come across such a policy?

Thanks in advance.