21 VS. 25

Islandtrader · #1 07-05-2010, 06:52 PM

Since there has been a plethora of 25 boats found and being restored I thought this would be interesting to the faithful.

I got this from this from big fluke a few years ago, and just now came crossed it today looking for something else.

Should be self explanatory.

cdavisdb · #2 07-05-2010, 07:26 PM

This one goes in my "longterm save" file. That is really great and helps me a lot in comparing what I hear and experience with these two hulls.

Quietly (very quietly) but I like the 21's shape better, for both ride and stability.

Now, where do we find a 21 hull shape in a 25 length?

Bushwacker · #3 07-05-2010, 07:34 PM

VERY interesting comparison Terry! Thanks for posting it! At first glance the 25 looks like a stretched 21! Deadrise angles are very similar up front, and it's obvious they came from the same designer! Interesting that the forefoot is cut away on the 25 at station 16. Maybe built for higher speeds in rough seas? Bob said he felt that his 21' "Unohu" was virtually impossible to broach in following seas with those large vertical steps! I think I like the 21 better in that area. Looks like the loss of buoyancy there may have been compensated for by more flare above the chine and in the longer bow in the 25. Maybe the extra flare is to make it a little dryer also.

Sure would be interesting to hear Carl discuss the differences between the two and why he made the changes! Would you be able to e-mail me that file? Would love to discuss that with him if I ever get to see him again! Denny

Blue_Heron · #4 07-05-2010, 09:43 PM

Quote:

I got this from big fluke a few years ago, and just now came crossed it today..

Very cool. Thanks for posting it. Bigfluke has been very generous with his expertise. It's a very interesting comparison. I understand Mr. Potter modified the design of the 25 before producing it. Did the Moesley design look more like the 21 stretched to 25'? I understand the 25 has all the bad habits of a narrow deep vee hull. I wonder if it might have been more stable in the roll axis if it had the shallower deadrise, but deeper steps of the 21.
Dave