I've noticed that with fin keel boats, I can usually sail into or out of my slip. However, with my heavy full-keel ketch at slow speeds, I often have to hit a quick blast of forward thrust to kick the stern around. With an upwind slip, I don't use much reverse while docking. When everything goes well, I don't need hardly any power at all. But the motor is just in case. The worst scenario is coming in slow and the bow starts to get pushed off by the wind. It's those situations where more power is helpful in keeping my boat off of my neighbors directly downwind while I back out to the main channel and set up for another try.
But this points to one of the advantages of electric drive. You can be sailing in with no motor on and if things start to get difficult, you've got full power available in about 1 second. No starting, no warm up, no panic. But my earlier point was that full power needs to be enough to handle the situation.
Eric
--- In electricboats@yahoogroups.com, Matthew Geier <matthew@...> wrote:
>
> On 06/04/11 05:16, Eric wrote:
> > John,
> >
> > As a sailor, I'm sure that you've tried coming into a dock with even mild (10kt) wind. On my boat, as I'm approaching the dock at speeds of less than 2kts, I occasionally need bursts of 2500W or more to stop or steer the boat.
> Interesting about how much people rely on reverse thrust as a brake - my
> boat, back when it was powered by a 2 cylinder two stoke engine, had no
> gearbox. The only way to get reverse power was to start the engine
> backwards (being two stroke it would run either way subject to spark
> timing). There was no way you could get the engine restarted in reverse
> in the short time frame required for using it as a docking aid.
>
> Thus I learned quite young, to dock the boat with out reverse thrust.
> My boat is only 5m long and 750kg which probably helps things some what.
>
> Now I'm lazy and give it a burst of reverse thrust to slow to a stop.
>
>
> I've watched people in rental boats trying to 'park' them like they
> would park a car. I was watching some one once who I was certain were
> going to blow the gearbox.....
>
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