Defever 49 RPH Stability

I'm sure it's a long shot, but does anyone have a stability curve for a Defever 49 RPH?

Also, does anyone know when Sen Koh switched from wood to foam in the boat decks?

I know most people suggest joining the DeFever Cruisers group, and I may eventually, but for now I figured I'd ask here.

Thanks!

I suggest you call Darrel Cottle at Jay Bettis Yacht Sales. 281 326 3333. They just got in a new 49 RPH for sale, and Darrel should be able to get the stability info easily if he doesn't already have it.

Avoid putting a huge dinghy and other add-on weight on the boat deck to insure the stability curves you get (try DeFever NA San Diego too) are based upon original intent.

Thanks for the tips.. I suppose I should have mentioned that I'm thinking about the 80's vintage Defever 49. I know the new ones are based off the older design, but I think the differences are enough that the stability curves may not be relevant. Although, I suppose they may be close enough for a rough idea, I'd guess the angle of vanishing stability would probably be within +/- 5 or 10 degrees.

If you have faith in NA as put forth by the experts such as DeFever, so long as you load the 49 as originally intended it will be very seaworthy. One of the questions to get answered in your quest is stability under varying fluid levels. DFs have large tankage and this weight and placement will figure into the curves.

Understanding stability curves assumes a bit of experience, that is why going to DeFever NA may prove helpful.

As a naval arch myself, I do have faith in NA. However, I also understand that boats are designed for an intended purpose and I don't want to assume the designers goal. The numbers will tell the true intention, but without actually owning one of the boats, it's hard to get the right numbers. I know Mr. Defever had a reputation for designing seaworthy boats, but how seaworthy? He obviously didn't design them to be self righting. While 800 gallons of fuel is significant, is it ocean crossing worthy? Probably not with twins, but the hull appears to be designed for a single setup as well. To me, the 49 looks like it should be fairly seaworthy, with the high bow and Portuguese bridge, but so do many others that aren't. It's hard to say without the numbers, what was his true intention for these boats?

To be honest, I'm really lusting after one of his earlier designs built by the Lindwall yard in CA, but I'm really not sure I want a wood boat. They're so pretty though

I'd be pretty surprised if there is any realistic stability data available, unless it's something created recently by an owner. Note there are two different DF 49 Pilothouse hulls, the earlier round bottom(1977-1986?), and the later hull with flatter aft sections (and less exterior teak) (1986-?).

I suspect that you're right, but maybe I'll get lucky and find an owner that had stability curves made for their boat and would be willing to share them.

I thought the difference in the hulls depended on where the boat was built, more so than the year? And that the difference is subtle.. at least that's what I gathered from an article I read about the boats anyway.

The only member that comes to mind that "may" have stability numbers on that boat had the screen name "baldpaul". He hasn't posted since he listed his for sale a couple years ago. Perhaps a private message could smoke him out.

I think Paul's 49 RPH was a 2004-5 though.

Might be worth asking Wilson Lin, of POCTA, who builds Defevers and is knowledgeable about the earlier designs. His email is on this Defever Cruisers site (not necessary to join to view it). DeFever Cruisers Links of Interest - A Club for Yachting Enthusiasts with a Passion for DeFever Vessels and the Cruising Life!

Other than a Defever 43 that sank in a freak accident when a large river tow it was passing on a tight bend reportedly sucked the water from under it--then hit it with a 4 to 6-foot wake--I've never heard of a Defever suffering a major knockdown or sinking. Has anyone else?

Tad,
I see where you state that DF's from 77 to 86 were rounded hulls and thereafter were flatter aft sections "hard chines?" What differing characteristics do each afford? I believe our next boat will be either a DF 49 or OA50 and am doing research now. Also, what about stabilizers. Were they aftermarkets?

Sam said:

Tad,
I see where you state that DF's from 77 to 86 were rounded hulls and thereafter were flatter aft sections "hard chines?" What differing characteristics do each afford? I believe our next boat will be either a DF 49 or OA50 and am doing research now. Also, what about stabilizers. Were they aftermarkets?

Click to expand...

There will be little or no difference in actual stability of the two different hulls as the dimensions and arrangement stayed the same. The difference will be in motion, the hard chine hull will damp out rolling more quickly. For most people this is reassuring, though it a snappier motion which can tire you out. The hard chine may also develop more dynamic stability when underway, and possibly run a bit flatter (trim less) at top speed.

Why is this of interest to you? Is there an issue you're dealing with? Honestly, the only way to measure stability on a specific boat 25 years old is to do stability testing on that specific boat today. Too many variations.

angus99 said:

Might be worth asking Wilson Lin, of POCTA, who builds Defevers and is knowledgeable about the earlier designs. His email is on this Defever Cruisers site (not necessary to join to view it). DeFever Cruisers Links of Interest - A Club for Yachting Enthusiasts with a Passion for DeFever Vessels and the Cruising Life!



Other than a Defever 43 that sank in a freak accident when a large river tow it was passing on a tight bend reportedly sucked the water from under it--then hit it with a 4 to 6-foot wake--I've never heard of a Defever suffering a major knockdown or sinking. Has anyone else?

Click to expand...

That was DF49RPH not a 43 that sank and it was due to pilot error.

Well, I wasn't there, but here's a picture and account of the 43 sinking. There are many other citations.

*GREY GOOSE ADVENTURES: Boating Accident - Narrow Fairway Lesson

Maybe you're recalling another?