Hi all
I am starting my de23 in the fall. I am anxious to know how she performs. Has anyone got one in the water? I was looking at a c-dory22 a production boat that is similar in a boat mag. Looks good!
Cheers
John
De 23 Performance
Keep in mind that the figures I post on the study plans are for the designed displacement. Mots of the DE23/25 I have seen were built very heavy, loaded with more equipment than what I planned for and as such require much more HP.
All boats of the same hull shape and same weight go at about the same speed. It doesn't matter if they are wood or fiberglass, mass produced or built by an amateur.
Dave Gerr explains that in his propeller book and in another one. It's called the Crouch formula.
Vk = C /SQRT (Displ/SHP)
where
Vk = speed in knots (not mph)
C = constant factor
Displ = displacement in lbs
SHP = shaft horsepower
For the DE23/25, use a factor C of 150.
Reports from our builders show that the formula applied to our boats are accurate within 5%.
All boats of the same hull shape and same weight go at about the same speed. It doesn't matter if they are wood or fiberglass, mass produced or built by an amateur.
Dave Gerr explains that in his propeller book and in another one. It's called the Crouch formula.
Vk = C /SQRT (Displ/SHP)
where
Vk = speed in knots (not mph)
C = constant factor
Displ = displacement in lbs
SHP = shaft horsepower
For the DE23/25, use a factor C of 150.
Reports from our builders show that the formula applied to our boats are accurate within 5%.
Jacques Mertens - Designer
http://boatbuildercentral.com
http://boatbuildercentral.com
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That's experience.
After calculating and checking a large number of boats, you get a good feel for what coefficient applies to a certain hull type.
Dave Gerr, Lindsay Lord and other give guidelines in their books.
After calculating and checking a large number of boats, you get a good feel for what coefficient applies to a certain hull type.
Dave Gerr, Lindsay Lord and other give guidelines in their books.
Jacques Mertens - Designer
http://boatbuildercentral.com
http://boatbuildercentral.com
Thanks Jacques
I was just curious to see some pictures of one in the water. I plan on 120 Hp. I only usuall do day trips and probably do not load it up much. I do seem to have a lot of gear I never use aboard my explorer though. I am looking for about 30- 35 mph. That gets me there safe then I use a kicker.
Here in BC it gets cold on the lake early so I need that cabin.
Cheers
John
I was just curious to see some pictures of one in the water. I plan on 120 Hp. I only usuall do day trips and probably do not load it up much. I do seem to have a lot of gear I never use aboard my explorer though. I am looking for about 30- 35 mph. That gets me there safe then I use a kicker.
Here in BC it gets cold on the lake early so I need that cabin.
Cheers
John
Hi-
I just posted a few pictures of my DE 23 that I launched last Friday. (on-the-water pix taken just prior to pulling it out yesterday)
I have done a limited amount of testing but am very pleased by initial results.
It is powered by a Yamaha 4-stoke 60 HP driving a 11.4 X 12 prop. Max GPS speed was little over 20 KTS with three aboard. However, I could not achieve the WOT recommended by Yamaha indicating I should reduce the size/pitch of the prop (max rpm was about 4800).
Rides well and gets on the plane around 12-13 kts. Stays on the plane down to around 8-9 kts. Very little change in pitch going to plane.
(notice waterline in the pix with speed <=5 kts or so).
I did not put any spray suppressors on the boat and it doesn't seem to need them. Do need to block the scuppers-fair amount of water sometimes.....
Questions?
I just posted a few pictures of my DE 23 that I launched last Friday. (on-the-water pix taken just prior to pulling it out yesterday)
I have done a limited amount of testing but am very pleased by initial results.
It is powered by a Yamaha 4-stoke 60 HP driving a 11.4 X 12 prop. Max GPS speed was little over 20 KTS with three aboard. However, I could not achieve the WOT recommended by Yamaha indicating I should reduce the size/pitch of the prop (max rpm was about 4800).
Rides well and gets on the plane around 12-13 kts. Stays on the plane down to around 8-9 kts. Very little change in pitch going to plane.
(notice waterline in the pix with speed <=5 kts or so).
I did not put any spray suppressors on the boat and it doesn't seem to need them. Do need to block the scuppers-fair amount of water sometimes.....
Questions?
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