As far as I know there is no ferry service between Dover and Belgium anymore. From Dover you have a ferry to Calais in France.
About 280 miles.
about 390km
By road, 77.2 miles.
22 miles
About 100 miles
How far is Amsterdam from Hamburg?
about a 10 minute ride by taxi
the coastline distance from southall to dover is approx 78 miles which is 1-3 hours drive
From Dover it is 514 miles
3900 miles
About the same distance as Baltimore to Canada.