I have just done the mission 'ferry from Ryde to Portsmouth.'
I did a calculation in the long time it took me to cross the Solent.
With an average speed over ground (from the info page) of between 30 and 31 knots and maintaining the required course, it took me 15 minutes to cover one mile.
I estimate this gives me a SOG of 4 Knots - my little outboard powered dory can go faster than that!
I gather some people have requested the facility of doing a port to port trip in real time. They should live so long!!
