View Full Version : iSonic 150

3rd May 2010, 09:26 PM
Heya, Was hoping to get some feedback for the iSonic 150. I am a 80 kg sailor, and am using a 180L formula with a 70cm fin, 11m severne overdrive at the moment.

Sometimes, the wind dies (not enough to plane upwind), I have a long boring slog upwind. I am going to receive my 2010 iSonic 150 w/ 58 &62 cam fin in a few days, would it be better upwind in planing and non planing modes? Took me a long time to decide on the 150 but I did cos the wind in Singapore is "extreme"!!!

Also, because I used to sail a longboard, does railing the board (formula/slalom) while not planing help with upwind ability? I am getting rather annoyed with myself for not getting upwind fast enough!

3rd May 2010, 09:43 PM

Nothing beats a formula board upwind while planing, but the iS150 should do really well.

I don't really know if the 150 will slog upwind better or worse than your formula board. I have done plenty of slogging on my formula board, but I have an iS 111, so there is really no comparison. My guess is that your formula board will still be better at slogging upwind than the 150.

While slogging, you must sink the UPWIND rail to work upwind, just the opposite of the planing technique (sink the downwind rail).

Actually, with the really wide boards (formula and iS 150), you should try to keep the board pretty flat if well powered, but the downwind rail will actually be 10 to 20 degrees lower. This "railing" will increase a little as the wind drops and you lose full power (hang in the harness and rail the board up a bit for maximum pointing).

3rd May 2010, 10:13 PM
That's strange... sink the windward rail to get upwind while slogging? Well, using a longboard, I have been taught to sink the leeward rail to go upwind...

I am having massive trouble slogging upwind with a formula and a 11m sail, to the extent I had to be rescued by the club's speedboat 2 days ago! ( I took well over an hour covering barely any ground...)

Also, Do you know if the iSonic 150's too big to enter slalom races? I heard it exceeds the width for a slolom board. Does that mean I cant race with it in any competitions?

Thanks for the quick reply!

4th May 2010, 12:08 AM
Yep - sink the upwind rail on a slalom / formula board to go upwind. I raced longboards for over 15 years and you are right - sink the downwind rail for upwind performance, but you have a dagger board and 12' of length to maximize your lateral resistance on the long board and that makes the difference.

Formula boards are dogs slogging upwind, but I have been in many races where the wind was 5-8 knots and those that could pump on plane could not get upwind any faster than those that slowly slogged upwind. The exception would be the very small and lightweight sailor.

Why do you sail so far downwind that it takes an hour to get back? Start upwind and keep upwind so that if the wind dies and you get stuck slogging, it's easy to get home.

Unless you are racing in the PWA (80cm maximum width), don't worry about the width of a slalom board. I don't know of anyone that uses the 80cm rule for slalom racing outside of the PWA. However, I am not all the familiar with worldwide slalom racing to know if anyone actually uses a maximum width rule, but slalom racing is usually held in moderate to windy conditions to accommodate the masses. It's unlikely that you will find a slalom race run in 8-12 knots where the iS 150 would excel. Once over 12-14 knots, the smaller slalom boards will have an advantage for the average size sailor.

4th May 2010, 12:28 AM
Hi Ken,

I will definitely try out sinking the windward rail, next time I get stuck! I was trying gybing and all, cos I just got a 11m sail, and am still not used to the weight while gybing, and thus ended up rather far downwind! Also, I have realized that in marginal conditions, not to try and plane upwind, but just point all the way! (learnt that the hard way).

I am from Singapore, where wind is rather pathetic, and I have been trying to keep a consistent speed with a mistral super vision 161. With a 8.5 sail, I always drop out of a plane and the local hardcore sailor who can pump insanely well always passes me! And thus my grand idea of using a iSonic 150 with an 11m sail... We'll see how that goes...

4th May 2010, 10:55 PM
As far as i know the maximum width rule for Slalom Boards is 85cm which the I Sonic 131 and 144 (both 85cm wide) both conform to. Here in Ireland and in the UK they use the maximum width rule in slalom events so we couldn't use the I Sonic 150 here for slalom racing so you need to check with the people organising slalom events in your country to check out if you can use the board

5th May 2010, 10:42 PM
I am having massive trouble slogging upwind with a formula and a 11m sail

I really struggle with slogging upwind on my formula board as well. The technique of sailing upwind by sinking the windward rail works brilliantly on my smaller and narrower boards however, I have never found it to be as effective on my formula board. I asked around last season about this very topic after getting stuck downwind a few times myself.

Seems like some recommend sinking the windward rail while others suggest keeping the board perfectly flat, moving forward, and maximizing lift from the fin. It was explained to me that sinking the windward rail in slogging conditions causes the board to plow through the water, impeding speed, and killing the flow around the fin such that it produces insufficient lift.

I am unclear as to which method works best and just wanted to pass along some other ideas to try.

6th May 2010, 01:12 AM
I am not sure as to what works, but I am sure that pumping into a plane and trying to to get upwind planing in marginal conditions really sucks... Gets me nowhere!

6th May 2010, 01:21 AM
Oh, and one more thing I dont get... why is it that people describe the iSonic 150 more like a large slalom than a small formula?

6th May 2010, 01:23 AM

I believe you are correct about the max width being 85cm, but the rule book on the PWA web site (2006 rules) states the max width is 80cm. I guess they have changed the rule, but not the rule book.


I have spent hours and hours racing my formula board in sub planing conditions in the last 8 years. I have tried - flat, sink leeward rail, and sink the windward rail. Sinking the windward works best without a doubt. Ask the people behind me.

6th May 2010, 07:26 PM
I think that Ken has a point about Formulas planning earlier than Slalom boards - everyone confirms that! I tried to sail one, but I thought it akward - do also prefer the iS150 or the new Light Wind (http://www.rikswindsurfing.com/live/jp-super-light-wind-gold-edition-2011-2379-0.html)boards :cool:

We have had a great discussion on the drivers of "light wind planning" in another thread. Some would even recommend you to go with the SB Phantom (http://www.star-board.com/2010/products/board_phantom.php)Raceboards, which can glide with ease in light winds and can certainly sail at extreme upwind angles (given their large daggerboard). Yet there was a lot of conversation on a statement made that Raceboards are more appropriate than Formula or large Slalom Boards for light-wind conditions:

So, let's try to be less polemic and a bit more objective about Raceboards (love your 320 though!). The German SURF magazine, compared in Aug'09 a number of boards in Lake Garda across a number of testers averaging 80 kgs utilizing specialized light-wind equipement. See the boards they tested and some of their results in the Tables attached below. [Check the difference between Formula and the medium-sized slalom Manta 79]


I very much agree with SURF's verdict on the Raceboards [my translation]:
[FONT=Tahoma]"The classic raceboard, 3.80 meters long, with an elegant Rail shape as a shipping container... can glide from as little as 4 knots; it runs extremely well up- & downwind and it may plan early in gusts with a folded dagger.
Still, it always seems huge, one simply feels that it was neither developed as a high volume board nor as a pure glider. While for a Raceboard-Cupper it's a must, as an Allround board on the lake with occasional gusts, an alternative. Those who come from shorter planning boards, will be disappointed by the comparatively slow-acting ride & driving experience."
That last sentence reflects my sentiment too. Consequently, I think that your statement about short boards destroying the market is a bit overblown! People like FUN, and fun is heavily related into speed from which some experience an adrenaline kick and freedom. Cruising is "cool", but planning is simply more fun. :cool:

Why is iS150 called a large Slalom board? Well that's exactly what it is! Build for speed in lower winds (9-16 knots), able to carry large fins and sails - check out the picture below. See an informal test and more picts in following thread (http://www.windsurfing33.com/forum/viewtopic.php?t=24710&start=0&postdays=0&postorder=asc&highlight=)

According to Remi: "This board cannot be used in the PWA rules but it's the perfect link between Slalom and Formula. For those who don't like Formula and prefer the glide sensation of an iSonic, it's the perfect machine for light winds with a sail around 10m". See also part of the quote from MarkH's comments...

iS150: Min wind in 10m, 8/10 knots (feeling ok powered, much more powered than iS144)
Ideal wind in 10m, 10 to 15 knots, feeling powered up nicely.


Bottom-line that is a different board than a Formula and is definitely NOT planning earlier! I am currently split between iS150 and another brand's light-wind board...

6th May 2010, 07:58 PM
Hmm, from this photo it doesn't look as huge as I thought it would be. I can see how the shape is somewhat a transition to formula.