Having been in one-design classes where boat weight difference can be up to 30+ pounds, I am wondering how important this is to people.
Also, something I have observed is that as fiberglass boats get older, they tend to get heavier (from absorbing water). And their original sails seem to get fuller (blown out). That combination seems to work well -- heavier boat, fuller sails.
But then the sailor decides he wants to get new sails. The new sails are flatter and sleeker, but they don't have the power needed to propel the heavier boat.
What do you think about all this? Especially, whether you think it is a big deal if your boat is heavier than somebody else's boat in the same one-design class -- or formula class, for that matter.
I think you have a couple of issues to deal with on this question. Construction methods have changed a bit and now
newer
boats don't gain weight as badly as the older boats. The reason being is the core or lack of core. A H14/16/18 has a foam core that absorbs water and that's where the weight comes in. H20's, I20's, 6.0's and most the other newer designs don't have cored hulls and don't absorb as much water. I can say that my old H20 was still under class weight even as a 10 year old boat.
The issue with those boats becomes stiffness and that can make a difference.
To those that care enough to change hardware to remove weight, yes it matters and is important. Relative speed difference? Typically it's a game of inches out front but good sailing will overcome 5-10 lbs or more of boat weight.
Hi Mary,
good idea to bring this topic to the general forum.
The impact of weight on performance is much smaller than many people think. Why? The first reason is, because heavy weight hurts only in light winds. As soon as you have to de-power the sails, the extra weight gives you more righting moment and you can use more pressure in the sails and hence you are faster (up wind). Down wind you are slighly slower in any wind conditions. But you win a race on the up wind leg anyway. (okay I have to say: I assume that the weight difference is in the hulls, not in the rig).
The second reason: If your 150kg boat is 5% over weight, then your total weight (assuming 150kg crew) is just 2.5% over weight. Somebody may play with texel or schrs calculators to find out, how many percent performance are equal to 2.5% more total weight. I guess below 1%. How big is the skill difference between sailors? Something over 10%, I guess.
Common understanding says heavy weights win in strong winds and light weights win in light winds. At least that is my experience in any sailing boat.
Another common understanding is: The reason why we lose races is because our boat is too heavy. The reason why we win is because of our skill of course. That's the reason why some people concentrate so much on weight. <img src=
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As long as you don't sail races only at light winds I would not care about these weight differences.
The impact of weight on boat handling at the beach however is another story. On our beach with soft sand and steep slope, we removed even the rudders of our Dart (which is only 140kg). Maybe we are too weak...
Last comment on weight: Every kilogram you can save in the rig is worth doing it, because it helps to righten the boat after capsizing.
About the new and sleeker sails, I don't know... I think that even a new sail has more camber than required. You have to pull it flat anyway. I have never had the problem of a too flat sail, but I know only a few boats of course.
Cheers,
Klaus
On the contrary, most modern boats do have cored hulls. And yes, all polyester/epoxy materials absorb water (they are hygroscopic) and gain weight. The boat doesn't even need to be in the water to gain weight...moisture is drawn out of the air and over time, it adds up (increase is something like 1-3% of the weight of the resin). Only way to really combat this is to put in the boat in an arid climate for weeks/months to dry out.
newer
boats don't gain weight as badly as the older boats. The reason being is the core or lack of core. A H14/16/18 has a foam core that absorbs water and that's where the weight comes in. H20's, I20's, 6.0's and most the other newer designs don't have cored hulls and don't absorb as much water. I can say that my old H20 was still under class weight even as a 10 year old boat.
The issue with those boats becomes stiffness and that can make a difference.
To those that care enough to change hardware to remove weight, yes it matters and is important. Relative speed difference? Typically it's a game of inches out front but good sailing will overcome 5-10 lbs or more of boat weight.
yeah but they're not the soft open cell foam of yesteryear and that was my point. the new materials are not as bad as the old ones.
Also, something I have observed is that as fiberglass boats get older, they tend to get heavier (from absorbing water). And their original sails seem to get fuller (blown out). That combination seems to work well -- heavier boat, fuller sails.
But then the sailor decides he wants to get new sails. The new sails are flatter and sleeker, but they don't have the power needed to propel the heavier boat.
What do you think about all this? Especially, whether you think it is a big deal if your boat is heavier than somebody else's boat in the same one-design class -- or formula class, for that matter.
Are you kidding? Boat weight makes a HUGE performance difference! (in your head)
Are you kidding? Boat weight makes a HUGE performance difference! (in your head)
That must be why Nigel/Alex beat us a Spring Fever our boat was 6pounds heavy and also my winter fat. I need to put myself and boat on a diet if I am ever going to have a chance of winning.
I guess the reason we came in 6th was that we had the next to heaviest boat at 409 lbs.. What's the best way to lose 10 lbs with your boat.
Sawsall.
![[Linked Image]](http://www.cpomilwaukee.com/images/product/large/0719-22.jpg)
Don't forget that each extra lb. of weight in the boat/crew is another lb. of water that water that has to be moved out of the way for each boat length travelled, plus additional skin friction/drag. Also within the same hull design a lighter displacement boat will generally turn more easily. The heavier boat/crews have to generate more power from the rig and have higher sheet loads.
Cheshirecatman
We race one of, if not, the heaviest boat in our class. The difference in weights, from lightest to heaviest, is minor (3.5%). Our crew weight is 20 to 30 pounds over minimum. We've had our best finishes in less than 10 knots of wind. This boat seems to be very negligable of crew weight. For us (weekend warriors) no big deal.
Relative boat weight? None of my relatives own catamarans so I guess I am OK. <img src=
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We race one of, if not, the heaviest boat in our class. The difference in weights, from lightest to heaviest, is minor (3.5%). Our crew weight is 20 to 30 pounds over minimum. We've had our best finishes in less than 10 knots of wind. This boat seems to be very negligable of crew weight. For us (weekend warriors) no big deal.
In my experience, boat/crew weight doesn't hurt performance in the light stuff and heavy stuff. Heavy weight hurts you worse in the medium conditions, where lighter crews can begin to fly a hull easier and earlier while you're still trying to power up.
Weight is major and to state otherwise is deluding yourself.
Mary, your assumption that the old sails better suit the old boat also has issues but lets keep it to one argument at a time.
A couple of case studies.
2 boats get perfect starts on a perfectly laid line. Assuming both boats are travelling at the same slowish speed when they cross the line the boat that gets to full speed first will have a definite advantage. If its the windward boat it will overhaul and then gas the leeward. If its the leeward boat its foils will generate more lift sooner (due to its increased speed) and it will pull ahead and then lee bow the windward boat. Either way the light boat wins.
You go around the top mark a boat length apart. If the lead boat is lighter it will accelerate away and the aft boat won't get a chance to attack. If the aft boat is lighter it will make up ground on the maneuver and be sitting in an attacking position when the two boats reach full speed.
If you do some quick back of an envelope calcs you'll see that without even considering the added drag while at speed at boat+crew that is 10% heavier will loose about 1/2 a boat length on every maneuver.
I didn't say weight didn't matter, or wasn't
major
. My statement was that in light air weight doesn't hurt as much as people think. I'll stand by that. I said extra weight hurts more in medium conditions, and I'll stand by that as well. I don't believe extra weight is automatically helpful in heavy air, but that's more boat dependent. So we're almost in agreement.
I'll say that every Hobie I've sailed/raced (14, 18, 20) wanted lighter crew (and boat) even in heavy conditions to sail better. The only time that being heavy didn't hurt was in light air.
The Nacras I've sailed and raced (5.8, 6.0, 20) haven't minded the extra weight as much in heavy conditions, in some cases it's helpful. But again, where it hurts most is in medium conditions, not the light stuff.
In light air so many other things matter. And, for almost everytime I've seen a lighter boat/crew out accelerate me as a heavier crew/boat I've coasted through the next lull as they slowed earlier. Actually keeping boats moving though maneuvers is key, and reduces the acceleration difference coming out - most people don't do it well in light air. If you're smooth a heavier boat can keep momentum better through a light air tack or jibe.
That's been my experience, spoken as somebody who has sailed ~400lbs of crew weight on a regular basis. If that makes me deluded than so be it!
Cheshirecatman
Here's my reason to lose a few pounds.
From the F16 Forum
What do you mean by
standard boat
? This is a formula class. As far as the Viper itself, the designer/builder says that if it were 18 kg lighter, it would be faster by only 30 seconds per hour.
In a big fleet regatta an extra 18 kg will set you back 30 seconds, possibly more on each downwind leg alone. More so if your crew weight is not down to optimum weight. You will be forced to run hotter angles then the lighter boats and they will just suck down inside you (if they are behind you) and gybe well in front of you. The boats in front will just stretch their lead further..... Hence it will cost you many positions..... Forget time. 30 seconds can be turned into 2 min 30 seconds over the course of a race within a big fleet as each boat passes you and feeding you gas.
I have raced my F18 carrying an extra 18kg of crew weight onboard and watched this happen many times. Then when I am sailing at min weight, the disadvantage is gone and you are doing likewise to the heavier boats.
Upwind also, the heavy boat will not accelerate off the line like the lighter boats (The most important part of the race) and it will not be able to sail with as much height or speed.
If weight was not an issue, then why do (most) manufactures strive to reach min weight and why do you see all the top sailors working very hard at reducing overall boat weight as much as they can espesially aloft. The serious sailors will even seek out removing grams from their boat.
Are they wrong, wasting their time or do they know something some others don't.
Just for arguments sake....
The quote above references 2 crew weights, which (to me) may mean two dfferent crew members. Could the performance difference you experience be related to having different crew onboard? Certainly crew work would reflect on your ability to get around the course/manuever/etc.
Just asking, as your assertation seems to be fairly general and COULD be misleading to the exact cause of the decreased performance.
No disrespect to the crews involved, of course.
EDIT: BTW I try to keep my boat down to minimum. I think it is challenging and it gives a mental edge. I just wanted to point out that there MAY be an issue with the general logic of the above-mentioned quote. End Lawyer-speak.
Sorry mate,
I wasn't addressing you in particluar, your's just happened to be the last post.
ive built a few solo ocean race boats in my time. the current thinking is that every extra kilo is worth about 4 hours on a rtw race.
There is a very good statistical analysis on the web:
http:/
I recommend to completly read it, because the author actually made two analyses. One simple normalised time to finish over weight (light boats are better even in strong winds). In a second attempt he realised, that the good sailors have in general lighter boats. He compared than the relative performance of each boat in different wind conditions and found that light crews/boats perform better in light wind and heavy crews/boats better in strong winds.
Another proof is, that top sailors are in general not lighter than average and that female crews (which are lighter in average) are not the faster sailor in average.
If you can't use the benefit of a heavy crew in strong wind, than maybe because you don't have the right heavy weight trim for your boat.
Cheers,
Klaus
Are they wrong, wasting their time or do they know something some others don't.
Basic marketing: If you want to sell a boat, you have to satisfy the wishes of the customers. There are also golf clubs out of CFRP and titanium and cars with four wheel drive which will never be driven outside of big cities, and so on. What counts is that they sell.
Every kilogram of resin, fibres or whatever is your boat from costs the builder something. Hence there is no interest in building heavy boats. BTW: manufacture costs and selling price are not the same.
Of course if somebody is convinced by the weight issue, his mind will be blocked until he get rid of the last gramm. As a marketing guy I would put even more fuel in this fire and offer extra sets of CFRP rudders and boards, dyneema sheets and so on.
Don't understand me wrong, I am very happy, that there are lightweight boats, because you can handle them so easy on the beach. But I concentrate on sailing and not on material.
Cheers,
Klaus
A heavier boat may in some conditions generate a higher righting moment however it is the ratio of righting moment to weight that drives performance. If Klaus is right I should be adding weight to my boat on heavy air days. I've never seen anyone do that.
A heavier boat only adds half of the extra weight to the righting moment, and multiplied only by the width of the boat: say 10 kgs of extra boat weight give 5kgs*2.5m=12.5 Kgm of righting moment; 10 kg of extra crew weight add 10kg*3.4m=34 kgm, practically the double of righting moment; boat of 2,5m width and crew of 1,8m assumed. This is why extra boat weigth is much more important than extra crew weight. Downwind it gives more or less the same disadvantage, at least for cats that go on two hulls downwind.
From my personal experience I we have found that older sails don't pay on a older boats in all but very light wind conditions. We gained a lot when we got new sails on our 1991 H16.
F=m*a...
Just for arguments sake....
The quote above references 2 crew weights, which (to me) may mean two dfferent crew members. Could the performance difference you experience be related to having different crew onboard? Certainly crew work would reflect on your ability to get around the course/manuever/etc.
Just asking, as your assertation seems to be fairly general and COULD be misleading to the exact cause of the decreased performance.
No disrespect to the crews involved, of course.
This has been experienced over many different crews, all very good sailors.
With my crew I sailed with for 7 years, we steped onto the Capricorn at 186 kg, and by the time the AUS Worlds came about, we were 164kg. We could feel the difference in the boat as we became lighter. Just after the Worlds, I had several different crews jump on ranging from 85kg to 65kg. VMG was better as the crews got lighter.
Exactly. It is quite obvious that the weight should be added to the crew and not the hull.
Also, bigger boats should increase the water ballast in the back of the windward hull.
Thanks for the reply, it certaily makes sense to me. 18 kgs seems significant.
One more question.... let's use 10 kgs wieght difference in this example. What order would you place the following (from most important to least important - obvioulsy all would help)?
1. New set of sails
2. Completely faired hulls, rudders, boards
3. Get boat/crew to minimum weights (10kgs)
4. Extra 5 hours practice each month
What else should be added to the list?
Thanks for the input.
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Time on the boat is always the key. 5 hours extra is not a lot but it helps. I would rather spend more time on the water than working on the boat to get it completely fair, to min. weight etc. etc.