Interesting Stats

[delevi]

I stumbled across this site http://www.sailingusa.info/design_winds.htm
which has a calculator to show you your boat's theoretic hull speed as well as it's rating (sail area compared to weight.) I plugged in the numbers for a Mac and here is what it showed:

Theoretic hull speed=6.45 knots. (using the LWL of 23'2")
Now I know that I consistantly blow past 6.45 kntos. Wait, it gets better.

Sail area Displacement ratio: 300 sq ft sail area (main and jib) at 4000 lbs (ballasted boat plus outboard) = 19.05 This classifies as a racer-cruiser.

Now, let's put a genoa on her. 380 sq ft sail area @ 4000 lbs boat weight, we get a sail area displacement ratio of a whopping 24.13. Guess what folk.. This classifies the Mac as a high-performance racer
Who would have thunk it?

[Currie]

Yeah, I've visit that one occasionally too. Here's another http://www.image-ination.com/sail.htm

I think they're technically accurate, though none of them account for semi-displacement (i.e. semi-planing) hulls. It's pretty much anybody's guess what happens once you start planing up. Pretty cool aspect of Mac's, actually.

~Bob

[Highlander]

Now you know why I cutter rigged my boat & she's a blast always draws a double take !!! & what the H_ll was that that just smoked us !!!

J

[beene]

Ya but that was when it was on the trailer going down the highway.



G

[Highlander]

Yeah she pushes that little ford ranger down the rd pretty fast also

officer said hi you cant do that the on 400 " 4 headsails into the wind " I said why not it really saves on the gas !!!

J

[dennisneal]

Maybe I should install outriggers??

[Frank C]

. . . I think they're technically accurate,
though none of them account for semi-displacement (i.e. semi-planing) hulls.
~Bob

One of them DOES account for semi-displacement hulls ...
by which formula the 26X hull speed computes to ~8 knots.

Here's another stab at debunking the Admiralty's formula, but easier reading. Naval architect David Gerr postulated a modified formula that allows for semi-displacement hulls. This excerpt is on the Potter Yachter website . . .

[gnomer]

Has anyone got on plane with M26? Is M26 able to really do it with full water ballast? And what are actually top speeds ever reached with M26?

[beene]

I tried it once, but the airline said I couldn't take it as carry on and had to be checked baggage.



G

[TAM]

We had some really strong winds on the Chesapeake a the end of last season. 20mph Wife was sleeping below so I was trying to keep the boat level. With only Main, we hit 8mph. On return, wife was up so I could let the boat go. Hit 9.8mph with genoa half out healed to 20deg. Awesome experience. HUGE rush . Was getting some really strange looks from captain of a Hunter 25 as we flew past. Realized our M was half out of the water, but still stable as ever. Not really expecting this sort of experience again.

[beene]

As far as the M being half out of the water, I find she heals real easy to about 35 deg. I would say I spend 80% of my sailing time on my M at 25-35.

G

[delevi]

Hit 9.8mph with genoa half out healed to 20deg. Awesome experience. HUGE rush . Was getting some really strange looks from captain of a Hunter 25 as we flew past

Now that's what I'm talking about!

[TAM]

I've stopped listening to anyone who says Macs can't sail well. If you know what you're doing, they're a real blast.

[beene]

If you know what you're doing, they're a real blast.

Could not have said it any better myself.

I would venture a guess that most folks who buy the Mac are first time sailors, more so than first time boaters in general. In such, can't get the sailing performance more experienced sailors can out of their Mac's. Not saying that some keel boats can't out point or out perform the Mac, just that the Mac makes a fine boat for all things fun on the water.



G

[Moe]

As far as the M being half out of the water, I find she heals real easy to about 35 deg. I would say I spend 80% of my sailing time on my M at 25-35.

I've watched an M owner who sails around all heeled over like that when everyone else isn't. He also probably makes the most leeway of anyone. Just an observation, but I don't remember ever seeing him reef the main (again, when everyone else has). He has a roller-furled genoa and it appears that's all he adjusts for wind. Why, I don't know. He's pretty skilled at maneuvering around the docks so I don't think he's a newbie.

Granted, it only had a working jib, but our X was never near that bad. At least 80% of our sailing was 20º heel or less, and most of the rest of that less than 25º. Yes, when overcanvassed and intentionally oversheeted, I could get it over further, but that wasn't the fastest way across the lake. Getting the main's center of effort down with a reef, while having some (partially furled) jib to balance it, was a faster, flatter solution.



From what I've read on this forum, it seems to me your amount of heel isn't typical of the M.

--
Moe