Anticipated speed of a baycruiser 23?

[Chris and Sandra]

Hi all,
We finally had some free time and settled weather resulting in a first sail. Was a bit surprised how fast the log suggested we managed. [ 8.5 and 9.5 knots on reciprocal headings beam reach in a solid force 4 ] It has been suggested we need to re calibrate the log. Boat certainly a joy to sail. I suspect rigging will get easier with time. Found retrieving easier than launching. Think we will need to figure out an arrangement to let us back winch. Garlieston slip is not that steep.
Any thoughts what  speed is likely?

regards

Chris and Sandra

[Rob Johnstone]

My experience with Vagabond (no 10) suggests that you were doing well. I think the fastest I ever recorded (mind you it was SOG so there may have been some tide in it) was just under 8 knots. Andy may have some other observations!

Riff Raff has yet to get wet, so I can't comment on the latest version!

[Andy Dingle]

I agree, I think those readings are perhaps hopeful. I presume they are from one of those spinny wheel thingy's.
I would expect 6's possibly even 7 knots in that sort of wind on a flat sea. Maybe take some gps readings (SOG) and see how they compare over time.

Re launching and recovery. I strongly suspect your trailer isn't set up properly - it took me ages with the help of a willing crew (Peter Cockerton!) to set the rollers up properly. What happens is the bilge keels get in the way of the rollers when launching and make it really hard to push off - the only way is to float the boat off. Recovery is a lot easier as the little bilge keels will roll over them. I could give you the measurements of how mine is set up if you think that would help? (I have a Snipe trailer). She really will just slide off, honestly!

Reverse winching makes life a lot easier - (though it is far better to set your trailer up properly). Take a thick-ish rope - non stretchy stuff! Secure it to the rear swing axle on one side, back up to the bow (over the top of the winching eye) back to a block on the opposite side, through the block and back up to the bow. Tie a loop in it well in front of the main axle. Take your winching strop back to this loop and clip it on, so when you winch it pulls the boat backwards off the trailer.

Regards

Andy
Equinox BC23

[Chris and Sandra]

re trailer roller measurements; yes please! Had a look at trailer. No-way the cradle rollers are missing the hull bilge keels. That would explain why the boat started to roll off then came to dead stop.
regards, Chris

[Graham W]

UK manufacturers seem to specialise mainly in livestock transport and trailers for boats are an afterthought. If it's good enough for a few terrified sheep, the thinking goes, stick some rollers on it and call it a boat trailer.

[Peter Taylor]

re. the speed: unless you were planing it is unlikely those speed figures are true. "Maximum" hull speed is calculated by the equation  A*square root(waterline length) where A is a constant typically taken to be 1.34 (if waterline length is in feet and the speed in knots). For a 23' boat that gives 6.4 knots. However the value of A varies depending on the hull shape and could be as high as 1.5 which gives 7.2 knots maximum. For a BC23 something between 6.5 to 7 seems likely which fits with Andy's experience.

The "maximum" hull speed can be exceeded by using lots of power, or by having a very fine hull design (think rowing eight, kayak, catamaran, etc.) or by planing. The limit is imposed by wave making effects. When you see a tug or fishing vessel using full power and creating a huge trough behind the bow which the boat is sitting in, together with a huge wake,  you know it's going at around hull speed and wasting power making all those waves

For a displacement sailing boat it also follows that once you are getting up to maximum hull speed you may as well reef because extra sail area is only making the boat less comfortable.

Any log which measures the flow of water past the boat needs calibrating since there will be regions beneath the hull where the water is flowing faster than boat speed and regions where it is slower. On Seatern the paddle wheel log placed to one side of the outboard well read low on one tack and high on the other. I gave up with it in the end. I now use GPS which has shown Seatern achieve a gratifying 10 knots and more (well, there might have been some current!).

Peter

[Rob Johnstone]

Re getting the bc off the trailer.
As stop gap, until you get the rollers set up, you can always use auntie mo (mentum). Before backing down the slip, make sure there's about 6 inches (alright 150mm) of slack in the winch rope and that the winch brake is on. Back confidently down the slip and brake HARD to stop. The momentum of the boat will keep it going and lift it up onto the bilge keels. The winch wire will then stop her. You can then let go the winch brake and give the boat a hard shove to get her launched. If you forget to put on the winch brake before backing down, the boat will fly down the slip when you stop.

Happy launching!

Rob J

[Andy Dingle]

Equinox logged 8.9 knots SOG today - Force 6 with a pretty rough sea..
We're both quietly impressed!


Andy and Equinox