On the last three trips we got the Moorings travel insurance. Not the best deal, but easy to add to charter contract and not too likely to be questioned.

Since Moorings have stopped offering that, we went with a policy by IMG sold through insubuy.com... about $150 for 2 people for 4 weeks.

Since we did not have to got through the BVI portal we didn't have to upload the policy. Someone may have glanced at it in the BVI, but certainly nobody was checking the details.