Hi George and thanks for the message. I'll do my best.
through France one needs an ICC
European Certificate of Competance as validated for the inland waterways through taking a CEVNI test (a test that one knows the Inland Waterways regulations). If you have Greek skipper's qualifications then I assume there is some way the Greek authorities (the equivalent of the RYA) could issue you with an (offshore, sailing) ICC
in which case the remaining problem is taking the CEVNI test. My understanding is that the RYA would allow you to take the test if you are resident in the UK (i.e you don't have to be a British citizen). If you are in the UK I can very much recommend you speak to our good friend and former instructor Roy May at Bisham Abbey - Bisham Abbey Sailing & Navigation School for RYA boat handling & shorebased courses
- the school
is based on the Thames near Marlow. You would also be able to get some inland waterways practice there.
If you have experience with boats/yachts offshore
then the skills you will have developed of boat-handling, judgement, COLREGS caution in the face of other vessels, etc. will stand you in excellent stead, inland. You'll just have to get used to going a lot slower. And so will your boat. Is she up to it? Big engines don't much like going slowly for days (weeks) at a time. I know of at least one motor
boat like yours that has taken six months to go from UK to the Med (stopping over at lots of places along the way) and has enjoyed every kilometre greatly.
If you've looked at my website you'll know about depths, so you'll know how your boat - and her propeller
- is likely to shape up. You will have to be careful to prevent your stern-drive(s) colliding with things (lock gates behind you, banks, etc). So far as using petrol is concerned, if she burns a lot then you've got to carry jerrycans (but I assume you need to do that at sea, anyway). There are fuel
stations alongside but not that many - be prepared in extremis to get fuel
from a service
station using a trolley or just lugging.
As for the skipper
and crew, well, you ought to be allright, provided you're used to living elbow
in a relatively small craft . . . !! And you take it easy and calmly for the first few locks, while you both learn the ropes and how to deploy them.