Hi Bill,
My experience is that you must show proof of insurance when checking in to most marinas and many harbourmasters over seas, and your insurance document must have the coverage clause in the language of the country you are visiting. Pantaneus, with whom we are insured, provides a standard document that has many languages covered.

Why not address the question to OCC friends at Topsail? I am certain they 'll be able to help you. They have a special page just for OCC members.

http://www.topsailinsurance.co.uk/ocean_cc.php

Vice Commodore, OCC 

Is it necessary to have proof of insurance when sailing to Azores? We are planning to join in on the Azores Rally in July and don 't want to be refused entrance because of insurance requirements. We have checked into many countries and have never been asked our insurance status, but have never been to the Med, or any European countries, and are confused about the requirements. We have insurance for the US, and are investigating "international" providers, but time is short. Can anybody tell us what their experience has been.
Bill Doar
s/v Advent II