ICC - International Certificate of Competency for pleasure craft and GOC
Need a radio operators certificate of competence and a ship's radio license.
From "Noonsite": Yachts must carry their original registration document, insurance policy, and ship's radio licence. One member of the crew must have a radio operator’s certificate of competence. An inventry of the safety equipment on board. For EU boats, proof of VAT status is also required. All crew should have valid passports (Citizens of some countries are required to have visas - consult Danish Embassy or Tourist Information offices for up to date information) – Noonsite aims to “provide a one-stop website featuring essential information on all matters of interest to sailors planning an offshore voyage anywhere in the world, whether already underway or still in the preparatory stages.”