controlling porpoising
06-08-2010, 06:22 PM
#11
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The porpoising comes from the boat trying to get up and run on top of the water and then falls back off. At the speed you are running is the breaking point of when the boat gets on top of the water or comes back down. Checkmate has a good hull design and their boats have no problem getting on top of the water and running with minimum power. Unlike a lot of boats that tend to push the water Checkmates hulls like being on top.
This is good because a fast boat is on top of the water not pushing the water. The bad is you get porpoising at mid speeds most all Checkmate Deep Vs do this. Seat time and trim down is the only cure Stock bravo 1 4 blade props seem to work best I feel in controlling the problem.
And their is nothing wrong with the drive to deep
This is good because a fast boat is on top of the water not pushing the water. The bad is you get porpoising at mid speeds most all Checkmate Deep Vs do this. Seat time and trim down is the only cure Stock bravo 1 4 blade props seem to work best I feel in controlling the problem.
And their is nothing wrong with the drive to deep
06-09-2010, 05:12 PM
#12
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So basically its just a trial and error kind of a situation
Would switching props to say a 4 blade help this problem or only cause it at different speeds?
Like I said that is the speed that is really comfortable to cruise at so it would be worth a swap if it would help
At least its a reason to go out and burn fuel or at least thats what I will tell the wifey
Would switching props to say a 4 blade help this problem or only cause it at different speeds?
Like I said that is the speed that is really comfortable to cruise at so it would be worth a swap if it would help
At least its a reason to go out and burn fuel or at least thats what I will tell the wifey
06-24-2010, 06:54 PM
#13
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curious as to how I can post pics .....Ive been told I cant post because I am only registered but I have seen a bunch of guys on here that are just registered who have pics posted
Would love to be able to show of my baby haha
Would love to be able to show of my baby haha
06-25-2010, 08:31 AM
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Hey Noyzee
I actually grew up in Peabody We have a couple mutual friends I think (The Perry Sisters) Scott and John
I go to the beach all the time not yet this summer though I used to have a P O S scarab last year and decided to buy a real boat this year
Id love to try that prop out if u wouldn't mind
I actually grew up in Peabody We have a couple mutual friends I think (The Perry Sisters) Scott and John
I go to the beach all the time not yet this summer though I used to have a P O S scarab last year and decided to buy a real boat this year
Id love to try that prop out if u wouldn't mind
yea, scott and john, yup. scott is coming out tomorrow as well.
should be fun.
was it the blue one? the scab?
06-26-2010, 05:56 PM
#15
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I have wanting to try a labbed hydro prop...I have been told that a labbed 25 pitch cut down to 15.25 inch is the way to go...It causes the stern to lift and stop the porposieing alot...which with a bravo 1 prop its a bow lifting prop and causes the porpoising more....
06-30-2010, 09:11 AM
#16
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Hi everyone
Reading your issues with porpoising, this is a hull bottom issue, more than likely you have a hook or bump in the bottom of your hull that causes this type of reaction while at crusing speeds, it very difficult to correct the problem with trim tabs and if you do correct the problem the boat will not be running very efficiently, you are causing major drag to keep the nose down.
Check the bottom of your boat, with the boat on the trailer take a stright edge and place it in line with the keel and move the stright edge out board, and see if you see light or the stright edge rockers.
JR
Reading your issues with porpoising, this is a hull bottom issue, more than likely you have a hook or bump in the bottom of your hull that causes this type of reaction while at crusing speeds, it very difficult to correct the problem with trim tabs and if you do correct the problem the boat will not be running very efficiently, you are causing major drag to keep the nose down.
Check the bottom of your boat, with the boat on the trailer take a stright edge and place it in line with the keel and move the stright edge out board, and see if you see light or the stright edge rockers.
JR
06-30-2010, 10:34 AM
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Hi everyone
Reading your issues with porpoising, this is a hull bottom issue, more than likely you have a hook or bump in the bottom of your hull that causes this type of reaction while at crusing speeds, it very difficult to correct the problem with trim tabs and if you do correct the problem the boat will not be running very efficiently, you are causing major drag to keep the nose down.
Check the bottom of your boat, with the boat on the trailer take a stright edge and place it in line with the keel and move the stright edge out board, and see if you see light or the stright edge rockers.
JR
Reading your issues with porpoising, this is a hull bottom issue, more than likely you have a hook or bump in the bottom of your hull that causes this type of reaction while at crusing speeds, it very difficult to correct the problem with trim tabs and if you do correct the problem the boat will not be running very efficiently, you are causing major drag to keep the nose down.
Check the bottom of your boat, with the boat on the trailer take a stright edge and place it in line with the keel and move the stright edge out board, and see if you see light or the stright edge rockers.
JR
06-30-2010, 05:29 PM
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Yup, WildWilly is right. Pulling the drive in a tich is the easiest. When you are in that mid RPM range with any positive trim they can start porposing. Pull the drive in a bit or give it more go juice.
07-01-2010, 07:41 AM
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i checked my hull. i had a few very minor imperfections in it mainly slight discoloration, could be just from the iron and cleaner used in the first 5 years the boat was on a lake taken care of by someone else. but i have layed a 4 foot straight edge out all over mine and cant find anything. i think some of it is the slight roundness to the V or maybe the small notch in the stern or a mix of both, but atleast on my boat its not a hook.
also, just about every 24-26 foot boat i have been in will have this issue at the perfect spot
also, just about every 24-26 foot boat i have been in will have this issue at the perfect spot
07-01-2010, 09:39 AM
#20
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OK
I was understanding that there were serious issues with porposing even when trimming the drive if its just a bump with the trim and its corrected, most all boats have that sweet spot for porpoising, it just a matter of knowing what to do with the boat to correct the problem, also most boats are designed for specific speed ranges and the type of boating you may be doing.
Many manufactures dont test their products through all the speed ranges to make sure the boat performs well through all the ranges, some boats are designed to go fast and handle rough water and others are designed for more family use for water sports ect and then there are those that try to hit several different markets, go fast, family, and water sports, and this is tough to accomplish because of all the different loads and center of gravity issues when developing hull forms.
Normally theres a forced compromise some where with in the design of the hull form to meet the customers needs and many times the customer is sold the wrong boat to fit their needs, but they want the cool looking boat, that the challenge to the manufacture and the design team, this is also where sometimes the manufacture is labled as a POS because the boat was not really designed for the proper market.
Just 25 years of my product development insight.
JR
I was understanding that there were serious issues with porposing even when trimming the drive if its just a bump with the trim and its corrected, most all boats have that sweet spot for porpoising, it just a matter of knowing what to do with the boat to correct the problem, also most boats are designed for specific speed ranges and the type of boating you may be doing.
Many manufactures dont test their products through all the speed ranges to make sure the boat performs well through all the ranges, some boats are designed to go fast and handle rough water and others are designed for more family use for water sports ect and then there are those that try to hit several different markets, go fast, family, and water sports, and this is tough to accomplish because of all the different loads and center of gravity issues when developing hull forms.
Normally theres a forced compromise some where with in the design of the hull form to meet the customers needs and many times the customer is sold the wrong boat to fit their needs, but they want the cool looking boat, that the challenge to the manufacture and the design team, this is also where sometimes the manufacture is labled as a POS because the boat was not really designed for the proper market.
Just 25 years of my product development insight.
JR
