Sailing to Windward

[hinmo]

Newbie here....yet to wet my CP16. I have heard these boats are poor to windward. With suspect sails, and standing rigging, and original flat rudder,  how close should I expect to be able to point?

Also, will I feel slippage when close hauled because of the shoal draft keel?

I am coming off a  34 and 25 ft fin keel sloops.

thanks for any input

[cas206]

I'm a non-racer newbie CP-16 too.  I have sailed a few times so far this winter.  The best two suggestions I've found on this board so far is 1) Keep her upright.  Keel works best that way.  2) Getting upwind seems to be quicker if you pinch slightly too high (slower water speed) than to fall off, fill the sail, increase water speed.  I don't remember if it was this board or somewhere else that GPS data from two boats seemed to prove number 2.

However, my own limited experience has been in stronger winter winds than in light air.  As always methods will depend on wind, waves, etc.  On the topic of waves, when a big power boat tosses a large wake my way, I usually try to take it at a 45 deg even if them means changing course momentarily.  This helps to minimize being knocked back.  Wakes are a bigger issue than with your 24/34 foot heavier boat.

[hinmo]

Thanks Cas. interesting.
Any slippage? or is that what you mean by keeping it up-right?

90% of my sailing will be in 1-2 ft chop, in 10-15kts

[Cats Paw]

Any slippage? or is that what you mean by keeping it up-right?

I would think more keel surface area in the vertical plane{latreral resistance} for possible better tracking  to point.

[mattman]

On the gps, I get 120 degree tacks, that is with leeway. I don't have my compass mounted, (puck style sliding on cockpit) but seem to get me about 50 degrees off the wind, which surprised me some. I thought she would be a bit tighter, but I did expect about 10 degrees leeway. I do try to sail her on her feet, but you have to watch the yarn and work hard to do this.  I have new Doyle sails this spring, full top batten, 5 oz main and 4.5 oz 110%. with a regular blade. I have only sailed with the ida rudder one time but in heavy air 18kts gusts at 26kts,  with just a jib though gps track did not look a lot different. I am interested in others' numbers on this. From what I can tell I am not seeing the better vmg by cracking off that others report. I am going to mess with a barber hauler this spring to see how that works out.  Come spring hopefully kickingbug and I will get to do some side by side comparisons. Although he has a roller furler his sails look good and we should learn a lot.  Happy Sailing, Matt

[cas206]

Thanks Cas. interesting.
Any slippage? or is that what you mean by keeping it up-right?

90% of my sailing will be in 1-2 ft chop, in 10-15kts

Yes..mast up ... keel down...none of that fancy sailing with the rub rail in the water.  I found the links that discussed pinching.

http://www.ipass.net/sailboat/sailtips.htm
http://www.ipass.net/sailboat/shoaldraft.htm

[hinmo]

ok - thanks
sounds pretty technical, but experience will tell

[Pacman]

When sailing a C-16 on a reach or beating to windward the old saying applies:  "When in doubt, let it out"

If the sails are sheeted too tightly the boat will develop excessive weather helm.  When that happens the rudder begins to act as a brake and the boat sails like a pig.  Let out the sails and she gets moving nicely and points higher too.

I sail my C-16 "fast and loose" with my sails sheeted in just enough to create some lift and with the rig as near vertical as possible. 

My GPS and compass confirm that "fast and loose" is best on my C-16

[hinmo]

When sailing a C-16 on a reach or beating to windward the old saying applies:  "When in doubt, let it out"

If the sails are sheeted too tightly the boat will develop excessive weather helm.  When that happens the rudder begins to act as a brake and the boat sails like a pig.  Let out the sails and she gets moving nicely and points higher too.

I sail my C-16 "fast and loose" with my sails sheeted in just enough to create some lift and with the rig as near vertical as possible.  

My GPS and compass confirm that "fast and loose" is best on my C-16

gotcha - didnt want nor expect a racer....just something simple

[kickingbug1]

    seems like my 16 sails faster with about 10 to 12 degrees of heel. i do tend to fall off and pinch up .

[Pacman]

    i do tend to fall off and pinch up .

Excellent technique and it works really well with the C-16.

Increasing boat speed by falling off a bit improves the efficiency of the keel and that allows the boat to point higher, at least until the boat slows down. 

Then repeat, especially in the puffs.

That's how the racers do it.

[mattman]

Some observations....
I race a lot (not the 16, some phrf but mostly one designs), and none of the boats that crack off get to the windward mark faster. What I see is they are slower on the same heading (sail adjustments, boat trim you name it) so they crack off with the hope of getting more speed however they never point higher even though they are moving better (now if they are moving to better wind that changes the dynamic....) If we were to crack off with them, then we might be the slow boat if we make an error in sail trim, boat trim etc. As i sail the 16 close hauled I get 10 to 11 degrees of leeway. Fall off 5 degrees and pick up 9-12% more speed and get about 9-10 degrees of leeway. So with wind out of the North and on port tack-close hauled gets us a compass heading of 50 degrees (which is the boat's point of sail) plus 10 degrees leeway is 60 degrees off the wind (this has been about the best I have seen on the gps). That leaves us with 30 degrees off of parallel to the windward mark. Crack off and we start with 55 degree compass plus 9 degrees leeway is 64 degrees off the wind and 26 degrees off of parallel to the mark.  Assuming we get 12% more speed cracked off but you have to sail farther... the 4 degree vmg difference is 13%. So it looks to me that we gain 9-12% in speed but lose 13% to our upwind destination. I think in a best case we arrive at the same time. Someone here have the trig acumen to actually do the math??? (It has been a long time for me and my sofa us just too comfortable). I think we forget that pointing the boat and vmg to the mark are two different things. As a caveat there are many articles that show that chasing vmg is not a reliable indication of sailing efficiency to windward as vmg begins to be a moving target depending on your relative position to the mark. In  sailing the 16, I have not cracked off of close hauled and done better to windward as I can see on the gps, the heading remains the same or less by a few degrees. I think that the leeway between close hauled and cracked off is actually smaller than in the example above. Until we get two boats out at the same time and do some runs we won't have any definitive outcomes. A final note, one skipper I crew with pinches all the time, I would love for him to crack off a little and get the boat footing better, however when we get to the windward mark we are always a boat length ahead of the other boats pointing just a bit lower.It is the same case as we sail downwind, he will seem to sail lower than I feel we should but invariably we always open or close gaps when I think we are doing just the opposite.  In this case my instinct is wrong. Nothing like side by side boat sailing to tell you the difference!!Happy sailing all...

[skip1930]

Yep without much hull speed in light air these CP's will basically drift sideways into the mark your trying to sail around.
Fall off and shoot under the mark. I use the navigation nuns as marks for practice. I missed one by a few inches trying to go around it instead of under it.
Won't do that again.

Rich Hutchins's clewed me in at the All Sailboat Show at Navy Pier years ago. "The CP-19 sails fastest when standing up". I did not ask about a CP-16 ... a hull designed by a different designer since I don't have a CP-16.

skip.

[cas206]

Some observations....
I race a lot (not the 16, some phrf but mostly one designs), and none of the boats that crack off get to the windward mark faster. What I see is they are slower on the same heading (sail adjustments, boat trim you name it) so they crack off with the hope of getting more speed however they never point higher even though they are moving better (now if they are moving to better wind that changes the dynamic....) If we were to crack off with them, then we might be the slow boat if we make an error in sail trim, boat trim etc. As i sail the 16 close hauled I get 10 to 11 degrees of leeway. Fall off 5 degrees and pick up 9-12% more speed and get about 9-10 degrees of leeway. So with wind out of the North and on port tack-close hauled gets us a compass heading of 50 degrees (which is the boat's point of sail) plus 10 degrees leeway is 60 degrees off the wind (this has been about the best I have seen on the gps). That leaves us with 30 degrees off of parallel to the windward mark. Crack off and we start with 55 degree compass plus 9 degrees leeway is 64 degrees off the wind and 26 degrees off of parallel to the mark.  Assuming we get 12% more speed cracked off but you have to sail farther... the 4 degree vmg difference is 13%. So it looks to me that we gain 9-12% in speed but lose 13% to our upwind destination. I think in a best case we arrive at the same time. Someone here have the trig acumen to actually do the math??? (It has been a long time for me and my sofa us just too comfortable). I think we forget that pointing the boat and vmg to the mark are two different things. As a caveat there are many articles that show that chasing vmg is not a reliable indication of sailing efficiency to windward as vmg begins to be a moving target depending on your relative position to the mark. In  sailing the 16, I have not cracked off of close hauled and done better to windward as I can see on the gps, the heading remains the same or less by a few degrees. I think that the leeway between close hauled and cracked off is actually smaller than in the example above. Until we get two boats out at the same time and do some runs we won't have any definitive outcomes. A final note, one skipper I crew with pinches all the time, I would love for him to crack off a little and get the boat footing better, however when we get to the windward mark we are always a boat length ahead of the other boats pointing just a bit lower.It is the same case as we sail downwind, he will seem to sail lower than I feel we should but invariably we always open or close gaps when I think we are doing just the opposite.  In this case my instinct is wrong. Nothing like side by side boat sailing to tell you the difference!!Happy sailing all...

Some armchair sailing math.  I hate trig so did this as vectors.  I considered the question, what condition does "cracking off" give an increase in velocity component along the wind direction.  I came up with:

Delta V / Delta Theta > Vo * tan( Theta )

How to use:  Vo is the speed over ground that you are initially making (what GPS says).  Theta is the angle between your initial motion and the windward direction (i.e. heading + leeward slippage, what GPS says).  Delta V is the change in speed by cracking off a small angle Delta Theta.  The left hand side (LHS) is some value fixed by your initial speed over ground and course over ground.  In order for cracking off to make sense, the RHS needs to be larger than the LHS.  This implies the change in speed should be as large as possible, for the smallest change in angle.  Hopefully that makes intuitive sense to anyone (anyone?) who might still be reading. 

This can be rearranged as a speed percentage as:
Delta V / Vo (x100%) > Delta Theta * tan (Theta) (x100%)

Using your numbers: Let Theta = 50 degrees heading off of the wind + 10 degree leeway (=60 degrees).  Your crack off example picks a new heading at 55 degrees but with only 9 degrees of leeway (=64 degrees).  So Delta Theta = 64-60 = 4 degrees (your better leeway makes up for 1 degree of the 5 degree heading change).  Changing to radians and putting into calculator gives

Delta V / Vo % > 12%

So you need a greater than 12% speed increase to do better than your present course.

A slightly better approximation would give:

Delta V / V (x100%) > 1 / ( 1/x - 1 ) (x100%) = 1/(1/0.12 -1) * 100 = 13.6%
where x = Delta Theta * tan(Theta)

[mattman]

cas206, excellent , especially the implication that we may all have quit reading half way through-priceless! Happy armchair sailing all