I want to improve the ability to of my boat (P18.2), not to mention her helm & crew, to sail closer to the wind. I was advised one way would be to bring my mast forward by tightening the fore stay (and loosening the side stays if necessary).
Does anyone have any comments or additional suggestions? I'm interested not just in any rigging changes, but also sail trim and anything else that enables a catamaran to cut a line closer to the wind.
Thanks.
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1998 P18.2
Sailing out of SHBCC, NJ
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Maximizing a Catamaran's Ability to Sail Close to the Wind
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Posted: Oct 15, 2018 - 11:27 AM
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Posted: Oct 15, 2018 - 12:24 PM
The general rule of thumb is to rake the mast aft for improved upwind performance, but that is very general, and my not apply to your specific boat. You don't mention in your post about what the specific issue is that needs to be improved with the helm, but personally, I would adjust the mast rake so that you have a slight weather helm and then leave it there.
My recommendation for improving upwind performance would be to install and use telltails on both your main and jib, particularly at the top of the main (2nd and 3rd panels from the top). If your boat is not performing upwind as well as you think it should, the first thing I would look at would be sheet tension. If you're not sheeting in all the way and the top 3rd of your mainsail is blown open, the boat isn't going to go upwind. Having telltails at the top of the sail will tell you immediately if you need to sheet in (as well as if you're over-sheeted). Telltails are probably the least expensive and most effective tuning aids you can install on your boat.
Also, don't get too hung up on pointing angle. Upwind performance is all about VMG, not just angle. If you're pointing 3 degrees lower than other boats, but going 25% faster, you'll still have better VMG.
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Posted: Oct 15, 2018 - 03:05 PM
+1 for all Dogboy said
as far as the mast position - i agree with using it to set weather helm but sometimes i will adjust up or down 1 hole in my sidestay chainplate to adjust for crew weight vs wind (i.e i will rake back 1 hole to depower when solo, in med - heavy air) -
other things to consider:
weight placement is critical for all points of sail
old (blowout) sails will have an effect on your ability to point -
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Posted: Oct 15, 2018 - 03:44 PM
+1 for dogboy and +1 for mn
I have given a lot of monohull sailors their first rides on a catamaran and most of them struggled with the concept of VMG (Velocity Made Good). Some never get it and continue their monohull habit of pinching upwind like crazy while everyone passes them to leeward.
Here is a basic explanation of VMG:
http://lagoon-inside.com/…anks-to-the-vmg-concept/
And an advanced one with lots of math:
http://hobiesailors.com/what-is-vmg---sm.pdf
Once you understand VMG and can execute it well in a variety of conditions.....then go buy new sails and enjoy the 3-5 degrees higher you can point and maintain the same VMG.
Brad
Stiletto 27 on a 2 year plan
Edited by bradinjax on Oct 15, 2018 - 06:09 PM. -
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Posted: Oct 15, 2018 - 06:10 PM
CatFan57,
Good advice here. You cannot change the laws of physics, if I may paraphrase Scotty.
In any beachcat, you are doing well to sail 45 degrees off the true wind direction. Closer than that requires a hybrid sailing craft. National 18-2 champion sailors like Richard Loufek (the designer of the Two), and Jay Glaser used to pump the mainsail and the tiller going upwind- using the waves if possible. They did this because the sails for the Two are cut for off-wind sailing, at which it excels.
In my experience, having difficulty going to weather in my Two has been a problem with my main sail. I had trouble with the controls, I thought, in flattening out the main for upwind sailing. The truth was I needed to replace the bolt rope sewn into the luff of my mainsail, as it had shrunk a lot and would not allow the luff to stretch enough, even though I increased the purchase in the downhaul. After I replaced the bolt rope (and the bungee inside the boom for the outhaul), sail control became a pleasure again - and sailing to weather with it.
Other considerations on the Two are the amount of mast rotation, loose vs. pre-tightened diamond wires, and are you constantly watching the luff on your jib to see if you are pinching, either unintentionally or on purpose?
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Posted: Oct 15, 2018 - 07:16 PM
Grashopper.... if it is knowledge on the Prindle 18-2 that you seek, your thirst shall be quenched with files in this folder....
https://www.thebeachcats.com/pictures?g2_itemId=119159
Enjoy
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John Schwartz
Ventura, CA
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Posted: Oct 17, 2018 - 02:04 PM
Wow, what a great set of replies all around! Many thanks to each and all who replied, and my apologies for not responding sooner. I have some replies/questions, but I think I'll break them up in separate posts.
Ok, so it sounds like the suggestion I received to move my mast forward was exactly the opposite of the standard advice. As I said in another thread, I think my helm is neutral, so I better rake the mast back a little to get some weather helm. Actually, I checked my owner's manual and noted there is a procedure recommended for setting your mast rake (by leveling your boat, then using a plumb line from the mast to measure rake), so I should probably start by following that, since I didn't do so setting up the boat.
The specific issue I'm seeing is that, even recognizing that catamarans don't point as well as other types of sailboats, I still think I'm not pointing high enough. I'm watching other cats sail closer to the wind pretty effectively compared to me. And I'm not just talking about new designs.
I do have tell tales on the main & the jib. I don't claim to be an expert on them yet, but I know I want the windward and leeward tell tales streaming back, and I watched these and other videos to get up to speed:
Main tell tales: https://www.youtube.com/watch?v=-J64a9GlP9E
Jib tell tales https://www.youtube.com/watch?v=aZGomgh5NJ0
I've tried various sheet tensions and combinations, and I've definitely sheeted in all the way on the main (with traveler all the way in) and jib, and still don't think I'm getting sufficient upwind performance.
I am aware of the general idea of VMG, although I definitely don't claim to be accomplished at making it happen. However, when I noticed my boat seems to excel at making high speeds in high power conditions when sailing off the wind (as compared to when sailing closer, where it doesn't seem to excel), I adjusted my sailing to start taking more off the wind lines and hoping the speed would make up for my lower lines. Nevertheless, it doesn't seem to be working that well for me (especially in low/moderate wind conditions), so by now I'm pretty convinced I should be able to do better sailing closer to the wind.
(Next post I'll reply to other comments, maybe get into what I've been trying regarding adjusting the jib sheet blocks location....)
Edited by CatFan57 on Oct 17, 2018 - 03:27 PM.
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1998 P18.2
Sailing out of SHBCC, NJ
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Posted: Oct 17, 2018 - 03:40 PM
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Posted: Oct 17, 2018 - 05:47 PM
One thing to remember with the 18-2, 19, Tornado, etc; those boats have centerboards and pinching is even worse in them than on daggerboard boats.
Edited by wlrottge on Oct 17, 2018 - 05:51 PM. -
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Posted: Oct 18, 2018 - 06:43 PM
My Gcat 5.7 was a dog to windward, I just thought it was an older, boardless boat and that was life. I got some brand new sails and it really gave the boat life. The downhaul became much more effective. The jib also had a slightly shorter foot for some reason, not sure what impact that has had technically speaking but she sails to wind like a new boat. Not saying spend $1000 or more on sails, but the bolt rope may be a could start -
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Posted: Oct 19, 2018 - 08:00 AM
Upwind, a larger jib is not really needed - think about all the high performance boats that have a self tacking jib (very small) - off/down wind size is king (those self tackers race upwind/downwind races these days and have a spin for the downwind leg)
it is pretty common for main sails, the boltrope and the fabric that wraps around the bolt rope to stretch in places and shrink in places too: making the bolt rope/luff to need either "releasing" or replacement.
I have had my bolt ropes resewn/replaced a few times in each of my main sails that are over a season or 2 old -
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Posted: Oct 19, 2018 - 01:53 PM
How do you guys determine when your sails are tiring or shot? Is it just assessment of their performance? Or is there stuff you can see just looking at them?
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Posted: Oct 20, 2018 - 09:53 AM
Thanks for the reply. I do watch the jib luff so if it starts to luff I back off. For mast rotation, I've been following what my P18.2 owner's manual says, which is:
"For most sailing, this rotation should be set between 60 and 75 degrees from straight back. A good rule of thumb is to have the wishbone pointing at the shroud when you are sailing to weather. ... When sailing to weather, an increase in rotation will flatten the mainsail, while less rotation will make the mainsail fuller."
So I've been setting the rotator so it points at the shroud when sailing to weather, and basically leaving it there the whole session. Not sure if I should be doing anything else when trying to point as close to the wind as possible. Someone recommended to me to have less rotation when trying to sail close to the wind(?). I don't quite understand if the last quoted sentence is telling me to do anything different than what I'm doing. I do generally understand that a flattened sail is de-powered and a fuller sail is more powered.
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1998 P18.2
Sailing out of SHBCC, NJ
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Posted: Oct 20, 2018 - 10:21 AM
Keeping the flow smooth across the mast onto the sail is key. If the angle is creating a detached flow, wrong angle I am afraid.
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Posted: Oct 20, 2018 - 10:39 AM
JohnES, thanks a lot for pointing me to these. I tried downloading the first one earlier this week and kept getting a "download failed" result. However, now it just downloaded, so I am looking them over, and can see they contain a "boatload" of valuable knowledge I really wanted to get into.
In fact, the first page says when sailing upwind in light air, I should have the "rotator pointed at the shroud chainplate," so that answers the question I just posted above - looks like I was doing that much right.
Another great thing I see is how to adjust the location of my jib sheet blocks fore/aft and athwartships. I was playing with those adjustments last time out, but having a hard time reaching conclusions in the light air conditions prevailing that day, so this is a real help.
One question though: the three guides are broken down into "Upwind", "Close Reaching" and "Downwind". What's the difference between "Upwind" and "Close Reaching"? I'm looking at the document MN3 posted above and the points of sail it's giving are "Close Hauled", "Close Reach", "Beam Reach" and "Broad Reach". I'm not seeing an "Upwind".
PS, by the way, thanks to MN3 for posting that document. Looks like it is saying a Beam Reach is the fastest point of sail on a catamaran(?). I didn't know that - thought broad reach was the fastest.
Edited by CatFan57 on Oct 20, 2018 - 03:31 PM.
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1998 P18.2
Sailing out of SHBCC, NJ
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Posted: Oct 20, 2018 - 11:19 AM
Close Hauled is upwind..the others are different angles of sail off wind with Broad Reach being downwind.
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Pete
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Posted: Oct 20, 2018 - 01:25 PM
i have to disagree a bit, there are other terms/angles that are still upwind
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Posted: Oct 20, 2018 - 01:37 PM
Lots of factors:
for me, i can tell if my leach is flapping
if my draft has moved forward and it's harder to flatten my sail
if i can't point as high as a new sail does (this newness is very short lived)
ALso, materials age / change differently:
dacron sails can live for "ever" if they are cared for and don't have chafe or rips but will continue to stretch forever and become less efficient/optimal ... etc with use and wind
more modern laminate sails often stretch (very little) and lose their race value pretty quickly but can be used for recreational sailing for a long time. the material will just fail at some point but can be patched and used (again very non optimal for racing) but can last for a long time - proper cleaning and storage will greatly extend their life
It's a bit hard to explain how to tell when your sails are blown without being very technical but basically what happens is the draft of the sail becomes deeper and moves forward (if i understood and remember correctly) and this has negative effects on the controllability of the draft
not a problem at moderate winds but a real issue in strong to crazy-strong winds
IF you ever purchase a new set, and they are made correctly to your boat .. it's like a great tune up and very noticeable.
we used to purchase used professional sails from Robbie Daniel (olympic level sailor/coach) at a heavy discount and modify them if needed to fit our mystere's. the sails were either experimental or races a few times and no longer new enough to be competitive - miss those days -
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Posted: Oct 22, 2018 - 12:32 PM
Oops, posted in wrong forum.
Edited by klozhald on Oct 23, 2018 - 12:07 AM.
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Sheet In!
Bob
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Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
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Posted: Oct 23, 2018 - 06:16 PM
Short answer. Your orignal sails are shot.
Long answer. The sail loses its shape. Look at the trimmed sail, does it look to have a shape like an airplane wing? A worn sail the max draft will begin to move back and resemble the shape of an inflated pillow case.
Sails can last a long time, but they loose shape rather quickly. Racing the F18, we see a difference in a single season. A new jib with good shape will likely really be beneficial to you club racing.
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