Correct volume calculation for new board buyers
I recently bought a Starboard Futura 122 ,but have found with my weight (100kg) that it's actually a "sinker" once the sail is uphauled (aka Titanic....). My skill level is such that I have been a confident rider of all the boards that I have owned previously over a period of about 18 years.
I would like to see some sort of calculator on the Starboard web site of correct board volume for new purchasers of boards to ensure that the correct one is selected(for the sailors skill level). At the moment I can ride the board but only if I uphaul real quick before the board slowly sinks(once the sail is lifted)which isn't really much fun and could be dangerous if the wind drops and currents unfavourable (Southern Ocean nearby....). Apart from shedding 15 or 20 kg or learning real quick how to waterstart, I think I maybe should have got the 133 or 144 litre board, as this would have given me that extra flotation and made the experience a bit more relaxing and fun. My point really is though,there is nothing to help calculate the correct size of a board which takes into account a riders skill level(I was FINE on my previous board..)and weight.... any thoughts on this ?
1l=1kg of flotation, so hypotheticaly speaking if your board is the exact same volume as ur wieght plus the wieght of ur kit wet, then it would sink all the way untill ir is fully submerged and then stop, but if u push down (as u do when you uphaul) the board will start sinking again. if you are planning on uphauling on it regularly with a decent size rig, 122l is for sure smaller then comfterble size. how big was your last board that you where comfy on it..? and how much does your full kit wiegh aprox? 144 would have probly made your life allot easier.... my sudjestion is to eather learn how to waterstart fast (very good skill to have regardles) or find yourself another board if it worries you, because it wont get any better over time unless you cut back in wieghgt on components of your gear, but 22kg for a full kit is cutting it quite close alread you want to have about 10-15 or even 20l extra after your biggest rig that your gona use on the board if you plan on uphauling on it allot comfy like...
anyways, my 2 cents for now,
I kind of agree with Tom here.
What was the volume; width, and length of your previous board.
I do not weigh 100 lg. (220.5 Lbs) so I cannot tell from first hand experience, but
I weigh 75-80 Kg and can comfortably uphaul 90-100 liter boards.
Perhaps your rig is quite heavy (mine tend to be very light, even in the larger sizes as I use 100% carbon masts and carbon booms in the larger rigs) and this is somehow adding enough weight to put you over the balance point between weight and volume.
Perhaps its a little bit of a technique (or adjustment) situation.
What part of your board is sinking? The tail.... The nose... or the whole board goes down level?
Are you sailing in freshwater or saltwater. The difference in buoyancy could make a significant difference.
Often with smaller lower volume boards the sailor has to make some technique adjustments to get their weight centered over the fore and aft center of flotation of the board (which may be in a different place than on your previous boards.
Do you put your front foot in front of the mast when uphauling?
If you are "centered" over the mast foot on your Futura 122 and the nose sinks, move your back foot back a little and slide your front foot back closer to the mast foot.
If, as you pull your rig up out of the water the fore/ aft balance is changing, you may need to change your technique to shift your weight a little to the rear as the weight of the rig is applied to the mast foot.
I agree, you are right near the "sinker" point, but there may be some things you can do with technique that will enable you to comfortably uphaul the Futura 122 that are a bit different that what you were accustomed to doing on your older board.
And, is the board simply sinking to the bottom when you beach start or is it simply sinking a little until most of the deck is awash?
Many sailors comfortably ride boards that float them, but most of the deck is underwater before they start moving.
Hope this helps,
I'm really amazed that you have been windsurfing for 18 years and haven't learnt how to waterstart. Waterstarting is a very valuable core technique that is actually quite easy to learn (and I was in my late 30s when learned to do it).
In fact, I learned how to waterstart the first day I attempted it, and I had no difficulty doing it on either tack. It was like a miracle when I first did it, and it was so easy. However, I had been sailing a longboard for about a year and a half, so I had developed reasonably decent skills. It was only after I bought my first short board did I try to waterstart.
Do yourself a favor and learn to waterstart ASAP. Ultimately you won't regret it, especially since you'll be able to readily take advantage of your new Futura 122.
Roger,the old board was a South Pacific II Bombora which was 292cm long and around 135 litres "REAL" volume. Having a look around on the Net it's become apparent that my idea of going to a shorter board (shorter is better ? ) was not such a wise move especially since real volume (ie. 1 litre displaces 1kg of fresh water or 1.025kg of salt water) is apparently different to "virtual volume" which seems to be some kind of nonsense marketing term that doesn't really help a lot with correct board selection. I would be interested to know if the Futura is a "real" 122 litres displacement or something less. The board DOES sink once the sail comes out of the water,so the sail,mast,boom,and myself with a WET wetsuit must be just tipping things past the "neutral" bouyancy point.
SteveC , The 18 years is on and off sailing due to living in a cold weather location,so most of this was concentrated over the 3 warm months we have here....so its a very on/off 18years. But yes your right,maybe I need to learn to waterstart,and probably more important, lose some weight.....!
p.s. some relevant links....
http://www.extremeforum.net/q-starbo...e-5661012.html (bad English ! ! )
this is actualy very interesting, ive heard of the "virtual volume" concept, but have never realy explored the topic much, im interested is there some sort of formula you can use to figure out the actual volume of starboard's currrent and past models...?
OK, now your dilemma makes alot more sense.
I'm pretty sure that the Futura 122 is pretty close to 122 liters, but the "volume
distribution" will be significanly different than your SP II Bombora.
The Bombora is 292 cm long and the Futura is 244 cm long and 76 cm wide.
So, you will indeed need to make some "adjustments" to your uphauling technique.
The volume in the Futura 122 is going to be significantly further back in the board, so
if you use the same "positioning" (relative to the mast foot) the Futura is going to sink by the nose pretty quickly.
If you adjust your "positioning" further back on the board to get your center of mass over the center of actual volume, you may find the Futura doesn't sink on you.
Also, longer narrower boards were/are not nearly as sensitive to fore and aft sailor positioning as the modern wider/volume further back boards like the Futura.
I would encourage you to sail the Futura a bit more and see if you don't find that once you make the technique change to get your weight back over the fore/aft center of volume, you will find the Futura does indeed have enough volume for a fellow of your weight.
Once you get the positioning sorted, I think you will find the Futura does everything your Bombora did, only more easily.
It's really OK for the board to sink so that just the tip of the nose and tail are out of the water.
The additional width should make uphauling far easier once you get the fore/aft position
I found exactly the same thing with really short boards like the Hypersonic 96 and the Compact.
They felt terrible and wanted to sink out from under me (even though both had plenty of volume) until I made the adjustment and figured out that fore/aft "balance"/positioning was actually more critical on these boards than side to side (athwarships) trim and positioning.
Once you get the rig up and the board moving forward I think you will find that there are no volume issues and will most likely find the Futura to be a really nice, fast, easy to jibe and easy to sail board.
Just try to change your "focus" from "side to side trim" to focusing on fore and aft trim.
Hope this helps,
The "virtual volume" concept was used for a few seasons when boards became wider. It was used to estimate how much volume a narrow board would have to have in order to give the same feeling of float.
The fact that some boards have less, or more, volume than indicated by its model number comes from first deciding what models there should be in a line, and then developing them. And it seems that in some cases the initial guestimates did not really match the actual board that became approved for prodution. Thus, no "virtual volume" anymore...
Im with Roger here, at approx 95kg naked I could uphaul a 110 HS once i sorted the for/aft trim. Practice in shallow water so you know you can when you need to.
However as stated by others waterstarting is an invaluable skill.
is 122- 113ltr
is 144- 137ltr
Why not to write the real volume on the board? Don"t understand! This is 2009 edition.
|All times are GMT +7. The time now is 02:06 AM.|
Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.