he has a small motor boat Yanita - suspect he would like a dead clam day really!

running across on a fine day from Dover to Calais in company would be OK adn coming back the same day in the same weather window is sensible however (1) you really will need it flat calm (2) there are far more interesting trips to be made in a boat like yours if you are feeling adventuous!
(1) Launch at Plymouth and run over to Salcombe for lunch then back
(2) Poole to Lulworth for lunch then Weymouth for tea back to Poole
(3) run around based at Milford Haven

If you have done these then there's always the run across to Ireland!