Spray Rails

[Meanz Beanz]

I'm bashing around the bay in an old Seawind 24 at the moment, they are a lot of fun but wet, wet, wet. Yesterday we where reaching in 25 knots of breeze in a confused chop with plenty of gear up. It was a bit like doing 17+? knots in a front loading washing machine only a touch wetter! Anyway I have been thinking about spray mitigation strategies and something I have never seen on multis is spray rails. I have read about power boats using them with some mighty claims of success. Does anyone know anything about how they would go on a multi?

[Meanz Beanz]

http://www.thesmartrail.com/photo_pa...ter_photos.htm

The photos are a bit sus, designed to highlight the positive. If they had repeated the first one with the rails on I would have been more convinced.

[masalai]

Have a careful look at my model movie. spray rails are almost non existent - being sanded off in the fairing process leaving only the "mark" but in the actual Chamberlin C10 does have significant impact. also look at video of the Maincat at http://www.mecat.com/indexpower.htm also if you can find it stuff on the Scheonning Vapour Trail 10m power cat built in Bris. No knowledge, but as an opinionated (*&%$#&*( Should also work but where to put it (how high above W/L?)

[Meanz Beanz]

Thanks Masalai, I have had a look at your vid. I will have a closer look now. The Maine Cat looks OK. I would be guessing the location but as there is not heaps of freeboard I would look at something like 1/3 of the way up the bow tapering back to the waterline for say 1/3 of the boat. I am trying to think of where I might find a suitable plastic extrusion similar to the Smartrail. They look good but the cost is on the high side when you go x2 hulls and convert back to AUD.

[waikikin]

Meanz, I had a Beach Marine cat with spray rails, only thig I didn't like about it was the spray rails- thought about adding a really big fat radius to em to quiet them down mostly at anchor or moored cos they where too close to the H2o & kept me awake in a short chop, even though they turned the spray down up fwd when this boat was really smokin' along she'd leave a very impressive "vapour trail". All the best from Jeff. PS: my new boat aint havin' no spray rails although I'm sure the're fine if possitioned diferently.

[Meanz Beanz]

Hi Waikikin, I seem to remember that the Beach Marine cats had a very square sort of knuckle about 1/4 of the way up the side. Is that right? Was it the Micro or one of the bigger ones? I use the SW24 as a day boat, the bay down here is not really good for cruising so I will very rarely sleep on the boat. So something that you would not recommend! I was thinking of attaching a moulding of some sort with Sika so that it could be reversed if it turned out to be a really bad idea.

Cheers
MBz

[waikikin]

Meanz, I had the 10M with bridge deck cabin, they tended to "aft trim" over the sports(open) bridge models especially when sleeping? as the main double berths where aft X 2 on a very narrow waterplane, also when driving hard there was a "less than progressive" increase in reserve bouyancy as the chine interfaced the wave surfaces- the upturned bell shape is much better to increase internal volume(part of the chines function on these boats as well as offering a conveinient bunk/furniture landing) on a narrow waterplane hull. If your all set to give it a go- yeah just glue em on with some silicone so you can shave em off easy! & try em out on one hull only so there's less to take off! & only bother with the forward 1/3 of the hulls! & shape them so they turn the water sheet on the hull DOWN so it lands back on the sea surface & not OUT so it still sparates from the hull but earlier & & is driven up by the beautiful breeze an impressive vapour trail that makes you wet & vortexes like liquid demonstration of maximum speed possible splitting the lovely spectrum of sunshine into a fabulous rainbow!! All the best from Jeff

[Meanz Beanz]

Ok thanks for that. I had in mind a curved bottom surface that pushes the water down into the surface of the sea as you suggest. Like you say pushing it out would just make the whole thing worse. I like the idea of fitting one side at a time, at least that way I can make a reasonable real time comparison between having them and not. At the moment I am not really sure I can find a suitable shape in a suitable material, I certainly don't want to hand over the kind of $$$$ the Smartrail people want for what is certainly an experiment.

I wonder if there is a really temporary way to trial it? Funnily enough we where pushing through the chop so hard that the hull deck join seemed to damp the spray on the odd occasion. That got me thinking about it, obviously under those circumstances you are going to get wet what ever but the main aim is to shut the spray down a bit in that 15 to 20 knot range, typical afternoon sea breeze stuff. That should keep a smile on the misses dial.

I will let you know if I have any luck with the idea.

Cheers
MBz

[masalai]

And pics too. Any ideas and information would be appreciated by me - even in the iron sail end of the exercise. Thanks....

As per someone more brilliant than I - some token points (real ones not allowed) . . . . . . . . .

[Richard Atkin]

The ol' SW 24 is still one of the fastest cruising cats in all conditions. Wonderful boat.

[Meanz Beanz]

Quickest submarine I have ever sailed

[Meanz Beanz]

Will do pics if I get that far !

[waikikin]

But how about the FUN:$ ratio, its gotta be the best around except for a pre loved beach cat. I just pulled mine apart for a rebuild especially around the chainplates & board cases plus plenty of other "fun" to grind out & repair being the patina of past Fun. All the best & enjoy a great peice of multi history & good vibes from Jeff

[Meanz Beanz]

They have to be the most fun for the least $ you can get. It will probably cost around 22K by the time I have it finished and that's with a few new sails, revised rig, a few mods & luxuries. I get a laugh out of blasting past the local heroes @ the local yachit club most of whom have spent 10x the cost of the old war horse that I have. Plus I can sail across all the bars and banks in the bay full tilt with out a worry. Seriously, a mate spent more on a new Hobie 16 than the SW24 cost me. Bang for buck they are an immense little craft.