Category Archives: Design Questions

Quick Boatsheds

I bought one of these sheds last year for $200. Moto-Shade.  10′ x 20′.  http://www.moto-shade.com/Product_Detail.aspx?Id=73

At that website they list stores where you can buy it. The UV breaks the plastic fabric down in less than a year, but tech there told me the trick is to get a new one under the 1 year warranty before the year is up. 

Its not big enough for a complete multihull, but many components can be built in one before the multi gets too big.

inexpensive boatshed

USCG 185 lb. Passenger Rule

I am learning more about the new USCG passenger weight and how it affects your stability letters. The changes are on:
170.170 metacentric height 

170.173 righting moment
171.57 intact stability
170.050 passengers heel
Boats with more than 49 passengers will also need their damage stability studies updated.

The added passenger weight does make most single hull vessels less stable.
It does however makes a catamaran more stable. Typically when I submit the stability calculations to MSC, I do the worst case; lightship. Lightship has no passengers included. The extra passenger weight makes the catamaran more stable. MSC understands that but advises that local offices may not.
So I have to run all the spreadsheets for both lightship and fully loaded with 185 lb passengers. And the attendant graphics illustrating what I’m doing. It looks like I can do the lot for 2 hours per vessel. I’m not sure yet how much time revising damage stability will take. I do need a copy of your stability letter and stamped sail plan (unless I already have them. I do have most.)
Due date is December 2011, but don’t wait until its too late.

Visitors Today

One of the perks of the job is getting a visit from sailors of KHSD boats who rave about the boat. Brian Bell and crew stopped by today. Based in New Zealand, their cruising ground is the South Pacific.  Somebody has to do it. Beautiful boat.

at anchor. notice the quarantine flag
underway