Assume this boat does not have the CE plate? Generally speaking it is usually easier to get the papers retroactive if it has been a official/commercial import. For private/grey import the paperwork is kind of unit specified, thus can be tricky to get retroactive papers for free...I would search for the box....
If the boat has originally been made for EU market, the Turkish manufacturer may send the paperwork against a HIN number, can be worth trying.
fun on a boat is inversely proportional to size...sort of anyway