If your boat is registered, you should carry it's official registration document or if it isn't registered, the bill of sale or other official proof of ownership. Although not mandatory, some European Union countries' customs officers may ask to see proof that VAT has been paid on the boat in the country of origin so it may be prudent to carry a copy of the VAT certificate with you. If your boat was built before the introduction of VAT you may be able to obtain an exemption certificate from your local VAT office.
Every member of the crew should have a valid passport and an E111 card.
Although not mandatory, it is sensible to carry your insurance documents (not copies) as some marinas may not let you in without them.
If you have a VHF radio on board, it must have a valid ship's radio licence and at least one person on board must carry a valid maritime operators certificate, upgraded as appropriate if you have a DSC model.
All boats entering from a country other than a 'Schengen' country, have to submit a Schengen form (basically a crew list) on arrival at your port of entry. The forms are available from port of entry Harbour Master's, but it is better to have copies on board before you leave and to have them filled out ready for inspection on arrival. The forms are completed in triplicate. One copy goes to the duty officer at the port of entry immigration whilst the other two remain on board for the duration of your stay. There are some minor differences in the requirements of different countries which can be found by following the links below.
Spot checks are increasingly being carried out and you can be fined as much as 75 euros if you don't satisfy the requirements. You may also be checked on your departure.
Make sure you have spare forms on board in the event that you change crew. Revised forms with new crew names should be submitted to the designated port of entry (details are contained on the forms) and both sets should be kept ready for inspection if required.
Customs should not normally be a problem unless you are carrying firearms (including very pistols or other flare guns), explosives, non EU members of the crew or dutiable goods. If you do need to clear customs, follow the normal customs procedures i.e. fly the yellow 'Q' flag on entering territorial waters and if a customs officer does not board straight away, report to the nearest customs official to get clearance.
