This is a reply to Dick:
As mentioned above (..ninth message from top..) “Our 1989(?) Ford Lehman uses about 5 litres an hour at 1600rpm, giving us a constant 7 knots.”
(I can’t make head nor tail of how these messages are organised!)
1600rpm gives us – in flat, calm-ish, still water, 7 knots. I may increase it to 1900 or – at most – 2100 if the tide and wind are against us ..to maintain that 7 knots (I always like to arrive on time). At 1600rpm with a 2-knot following tide, that’s 9 knots (we’ve sailed, with a following force 6, at 11.5 knots).
With a 2-knot tide against us (..there’s always a while, going the 9 hours from Ramsgate to Eastbourne, when the tide turns after Dungeness..) I usually go up to 1900rpm to maintain as far as possible that 7 knots ..so 7 knots x 9hrs gives us that 63 miles from Ramsgate to Eastbourne.
Once again, it’s about 5 litres an hour at 1600rpm.