You can go to the older list archives on the MSOG site and search for "flotation" or "floatation" and get about 25 messages on the subjevt. I didn't read them all, but there ought to be something useful in there. From an earlier discussion on flotation for the 17, maybe you can do a calculation for the 15:

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From: CWPBaker@aol.com
Subject: Re: M_Boats: M-17 flotation
Date: 30 Apr 2001 16:30:30 EDT
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I asked Bob Eeg that same question & he said that a large truck inner tube forward & one aft behind the quarter berths gives the M-17 positive floatation. C.Baker"
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At 12:02 AM 7/22/02 -0700, you wrote:
>
>Does anyone know what what volume of baddered air would equal the bouyancy
>of the styrofoam blocks under the v-berth of the M-15. I would like to get
>some additional dry storage room by using an air badder to replace the foam.
>Thanks in advance for any input. David (no6m@hotmail.com) M-15 #318 (boat
>has no name)
>
>
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Doug King
M-17 #404 "Vixen"

Montgomery Sailboats Owners Group Web site: http://msog.org
Email: mailto:msog@msog.org