No precaution needed there IS 3 pin sockets just take an extension lead for additional items as there is only one above the dressingtable. You can get a lap top on board or buy wi fi access for your own as well as theirs. see the IT consultant in the internet cafe.
I am told sea princess has english socket.
The Sea Princess has english sockets fitted when it was P O Adonia.
Your on holiday leave your lap top at home.
As a precaution why done you take 1 each of US and EU plug adapters and a small extention cable which has several uk plug sockets (you always seem to want to use more than one UK appliance at a time) Hope this helps.