Page 1 of 1

Strange Things Can Happen When Racing

Posted: January 19th, 2019, 7:49 am
by Bill Roberts
Here's a picture taken during the 1981 Round Island Race Ft Walton to Pensacola and back. The picture was taken from the Destin Bridge 5 miles into the race. As you can see the RC27 #1 is at the bridge and the fleet seen in the top of the picture is about a mile back. The winds were light. Every one was moving very slow, not even a ripple at the bow on the 27. How does this happen?? How does one boat get 1 mile ahead of the fleet after only 5 miles of racing?
Hint: The lead for the 27 was not due to boat speed. How did this boat get so far ahead in 5 miles of racing?
1st RC27 Round Island.jpg

Re: Strange Things Can Happen When Racing

Posted: January 22nd, 2019, 1:03 pm
by Bill Roberts
OK gang, talk to me. How does one boat out of a large group sailing in the same direction in the same water in almost no wind and a tidal current get one mile ahead after 5 miles of racing? Every boat started at the same time on the same starting line heading in the same direction on a close reach. There was almost no wind. Look at the bow of the 27. There is no spray, not even a ripple.

Re: Strange Things Can Happen When Racing

Posted: January 24th, 2019, 4:35 am
by T Peterson
Hello from Cuba - bored at the moment so thought I’d take a look here - I have only seen Hobie Cats here so far.

As for the photo I think I see boards up, one or both rudders up, weight forward, and sails trimmed in. I’ll even hazard a guess that the jib looks over-trimmed but it’s hard to tell. If the leeward rudder is indeed up, that seems unusual to me, I lift the windward rudder to reduce drag. Or, covering more bases, river current or tidal current.

And finally, I once beat 40 A fleet Hobie 16s in a regional race, coming in first. It was a floater and pretty much luck.

This is where Bill tells me one of the above is close...

At least in no wind, this thread won’t result in a righting discussion!

Re: Strange Things Can Happen When Racing

Posted: January 24th, 2019, 11:11 am
by Bill Roberts
Hello T Peterson,
Thanks for your comments.
The advantage position of the 27 relative to the rest of the boats racing has nothing to do with boards or rudders, leeward one or windward one, or weight forward or sail trim. There was little to no wind to trim the sails to. The jib has the shape it has because if its own weight. There is no wind to push the leech open. The sail is hanging down like a shower curtain. The 27 is in the position it is in relative to the fleet because of choices made by the 27 sailors earlier in the race.
Notice this 1981 picture was before square top sails and self tacking jibs. Look at the roach in that mainsail. Back in those days it was common sail design practice to put ~33% of the mainsail area in the roach. This is not a hint to the question.

Re: Strange Things Can Happen When Racing

Posted: January 25th, 2019, 7:57 am
by Bill Roberts
OK here's how it happened.
The race started at 8:00AM, daylight but the sun not up yet. Race started in a bay. First mark was to the East about 4 miles. Then round this mark, turn right about 90 degrees and head south out the inlet to the Gulf. Go out the inlet and turn 90 degrees again and head West to Pensacola Inlet sailing West for about 50 miles.
There was little to no wind at the start. Every one was even and headed east. The first mark not in view yet as it was in the shadows of buildings on the east shore. Finally sun gets high enough to see the first mark. Fleet was down the bay a mile or so from the start. Seeing the mark, the 27 sailors noticed that the mark appeared to be moving north, to the right, along the east shore line. Now we know the mark isn't moving. The only way it could appear to be moving north was if we, the 27, was moving south, to the left. That told us that there was a current moving east and south down the bay. The 27 headed up above the mark until the mark stood still against the east shore line. That meant the path of the 27 over the bottom of the bay was directly toward the mark even though the boat was headed well above the mark. Every one was still drifting East and no one noticed the 27 easing out to the North edge of the fleet. Later the 27 noticed they had to head even higher to the north to make the first mark stand still against the East shore line. As we were getting closer to the inlet, the current was becoming stronger to the south. Therefore it was time to "put some money in the bank"and head even more to the north, make the first mark appear to move south slowly against the shore line. Now our path over the bottom was slightly above the mark. We could always come down to the mark when we got there and round, but when we got to the mark, if we were low, we could be in big trouble getting back upcurrent to the mark. We came to the mark high and rounded easily and headed South for the Destin Bridge in a drift and with the current. This is all taking place in super slow motion. As we got to the bridge, we looked back and saw no one had rounded yet. As a matter of fact there was a parking lot of boats developing below the mark trying to get back to the mark against the current. When we had gone under the bridge and could still see the first mark, no one had rounded the first mark yet.
So learn a lesson here. When ever you are headed for a mark, if there is land or buildings beyond the mark, check to see if the buoy is standing still imposed against fixed land, objects. If the buoy appears to be moving, there is a sideways component to your boat velocity, so alter your course until the buoy is standing still and then your path over the bottom is directly toward the bouy.

Re: Strange Things Can Happen When Racing

Posted: January 27th, 2019, 1:30 pm
by Bill Roberts
I'm waiting to hear something from somebody. Did everybody know to do what the 27 did in this race relative to racing around buoys? Has anybody ever heard of this? In this race it looks like only one boat out of 30+ boats knew what to do. Is this "common SC knowledge"?

Re: Strange Things Can Happen When Racing

Posted: January 28th, 2019, 7:24 am
by T Peterson
Except for crossing the Atlantic twice (on a monohull) I am a lake sailor and have no experience sailing in rivers or currents. I’ll bow out.

Re: Strange Things Can Happen When Racing

Posted: January 28th, 2019, 1:53 pm
by Bill Roberts
Hello T Peterson,
I learned to sail in currents as a middle teenager. I sailed a Snipe on a reservoir
along the Tennessee River near Chattanooga. The current was stronger on the West side of the lake.
It made a big difference in light air races. On a windy day it did not make much difference.
That is where I learned the relative motion test to see if you were making a mark or not.