Please help me understand ISAF Special Reg 3.09.7 'Cockpit Volume'

[jgsteven]

Hello,

I am trying to understand ISAF Special Reg 3.09.7 on cockpit volume*. The reg states:

"the total volume of all cockpits below lowest coamings shall not exceed 6% (LWL x maximum beam x freeboard abreast the cockpit)."

Seems straightforward, but if I do the calculation:

25 ft LWL x 9.6 ft beam x 2.75 ft freeboard by the cockpit x 0.06
= 39.6 cu. ft. maximum cockpit size

That seems really, really small (2ft deep by 4 foot wide by 5 ft tall!).

My boat's cockpit is not overly large, but is still around 96 cubic feet (8 ft x 4 ft x 3 ft). Even if you subtract out the molded fiberglass seats, its still around 64 cu feet, or double the limit.

My questions are:

1. Am I understanding this reg right?
2. Is there a solution to this? Glassing in 32 cubic feet of foam to reduce volume? Lowering the cockpit coamings?

Thanks,

Joe

* note: this reg applies to age or series before 4/92

[Giulietta]

JG, it's actually 9% not 6%, and that is to compare with the volume of the cockpit bellow the lowest coming.

From your measurements: 25x9.6X2.75x0.09= 55.6


You have a maximum allowable of 55.6 feet you can not exceed.


So you have to measure the volume of your cockpit, but from the top of the lowest coming to the cockpit floor,

height of lowest coming X Lenght X Width...that number has to be inferior to 55.6 feet

Alex

link to ISAF Appx J cat5

[GeorgeB]

Forgive me, but I do not have the ISAF book here at work so I can’t quote, but I think the intent is to measure the total volume of water in the cockpit before draining. So it should be the lowest coaming except for the bridge deck before the companionway. What boat do you have? My Catalina passed ISAF Ocean 2, but I have a sugar scoop stern. My bridge deck/companionway threshold had to be at least as high as my cockpit seats which I achieved by fixed mounting my lower hatch board in place. In the for what it’s worth department, I’ve been pooped twice (once severely) and in retrospect, it wasn’t so bad as none of us got flushed out. I was surprised how quickly we drained once the stern got out of the wave. We did have the hatch boards in place and the slider closed so we had the minimal amount of downflooding.

[Giulietta]

Joe, after posting my initial post, I tried to edit, because it was missing stuff and Sailnet crapped on me and I couldn't do it.

Now I edited it so it's clear.

George is right, it has to do with the maximum water allowed to be held in the cockpit

[sailingdog]

Basically, this is to limit the volume/weight of water that the cockpit can contain in the event your boat gets pooped.

JgSteven-

You screwed up your measurements...the units should be CUBIC FEET...not square feet.

I am guessing that your cockpit is 8' long x 4' wide...and the three feet is the height. However, I doubt that is the lowest cockpit coaming level... If the lowest cockpit coaming is 2', the total cockpit volume would be 64 cubic feet, and according to Gui's measurements, you are allowed 55.6 cubic feet, so you'd need to glass in a volume of 8.4 cubic feet. In your cockpit, you could create a bridgedeck expansion locker that was 1.5' x 4' x 1.4' or so.

[jgsteven]

Originally Posted by sailingdog

You screwed up your measurements...the units should be CUBIC FEET...not square feet.

Hi Saildog,

Yes -- you are exactly right. I should have said cubic feet (a measure of volume) not square feet (a measure of area). Thanks!

Anyways, I located the regs online at US sailing's website (System won't let me post a link, but you can Google to 'US Sailing ISAF Special Regs')

It seems category 2-4 is 9% of LWLxFreeboardXBeam while Category 0-1 is 6%. So I can probably reduce coaming height or glass in a box somewhere to get to cat 2 pretty easily, but category 1 may be out of reach.

Thanks to all who replied for their help!

Regards,

--
Joe

[sailingdog]

Glad to help JG. BTW, I did something similar to build the bridgedeck on my boat, and if you want to see the pix, let me know.

[chucklesR]

Rules like this, while well intentioned, just don't and can't apply to catamarans.

I'm closer to 8 feet wide by 6 feet long by 3 feet deep, and I'm a small, skinny catamaran.
Glassing it over just to compete in a ISAF sponsored race is wasteful.

[GeorgeB]

The point of the ISAR regulations is to keep everybody alive. 95 cubic feet equates to some three tons of water holding the boat down. That is almost half of my boats total displacement! And all that water has to drain down two one inch drain lines before the next wave hits. I am curious on what race jgsteven is entered? On the west coast the only Cat 1 races I know of are Vic-Maui, Pacific Cup, Transpac and Los Angles-Tahiti. With the loss of Daisy and Pterodactyl last year, our local Coast Guard is forcing our OYRA and SSS to adapt Cat 2 as a requirement. Fortunately they have waived some of the more onerous requirements. To put things into perspective the Vendee Globe boats are all Cat 0.

[jgsteven]

Hey George,

Originally Posted by GeorgeB

I am curious on what race jgsteven is entered?

I haven't entered anything yet. I would really like to do the Pacific Cup in 2010, however right now I am just trying to understand the regulations and evaluate my boat for 'offshore cruising ability'.

It seems the 2008 Pacific Cup was done by a number of people in what I would consider a very small boat to cross the pacific in (ie: Moore 24, Express 27). I am very interested in going to Hawaii at some point (whether in 2010, or in some future year and future boat) and have been looking into the regs as a good starting place to understand how to make my boat safe offshore.

SailingDog-> I would love to see the pics of your bridgedeck install, if you could post them.

Regards,

Joe