Hi Depends where you leave UK from Dover 20 miles so 3.5 to 5 hours
Weymouth 70 miles 12 to 15 hours
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Presently at least there is no service from Weymouth to France or the Channel Islands. The former operator upped-sticks - or hawsers - and now operates from Poole, about 30 miles away. There is now (late 2015) a new company considering a service from Weymouth again, but this is still in planning & negotiation.
don't sail, fly
It takes two hours from the UK to France.
Around a fortnight depending on the vessel.
5 months and a half
around 8 hours
3 weeks
1 month
In the 18th century about 6 months
about an hour
France
Franklin served as the U.S. Ambassador to France from 1776 till 1785.
2 hours