Can't unfortunately accompany you but the gated marina at Le Harvre is secure and well served for vistor's moorings by way of walk ashore pontoons and relatively easy to find/access. The harbour office is in the far left hand corner of the marina. The petrol is on a pontoon in the far right hand corner of the marina and is self-service 24hrs a day at similar prices to French road service stations. There is a maximum delivery limit (from memory: 100 litres) so you may need to insert your card more than once.
Deaville is tidal but is an attractive place with Honfleur (spectacular!) just round the corner. Has diesel-not sure about petrol.
Just watch out for the nose-to-tail tanker traffic going up-river!
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Brian
"Ribbing-the most expensive way of travelling third class"
Thank you for advice. Le Havre seems to be the best candidate. Dates are firmed up to Thur 1st from Lymington back about 4 days later. We are still keen to find a crew member. Cross channel in a 6.5m as a solo trip is a bit scary for us without someone else to listen to for wisdom and advice!