If you mean sail on a sailing boat - about 2 hours. If you mean by ferry, about 30 minutes.
It all depends on the type of boat you're using.
how long does it take to drive to Nottingham from Portsmouth
It takes about 12 hours by road to get from Aberdeen to Portsmouth.
how long does it take to sail from Pakistan to England
10 days
8 hours
how long wil it take to sail from RSA to Odessa
It takes 16 hours to fly from Phoenix to Istanbul.
252 days was how long it took
how long dose it take to lancing to portmouth and back
you can't fly to Portsmouth I am afraid,no airport,London airports are the nearest.