Ideal boat list (or lean to one side)

Has anyone calculated the ideal list for a clean surfable wake? It seems to be 10 to 15% I think a good way to calculate it would be to measure the height (or depth) of each corner of the swim platform, find the difference between the measurements for each corner, then divide by the length of the platform. If we can quantify the amount of list, we may be able to provide better guidance for those who have trouble producing a surfable wake.

(Message edited by Jimgalloway on August 16, 2006)

amount of deadrise in the hull seems to play a role also.

Jim, I’ve been thinking about this issue, I think I'd like to know yaw (list) and pitch (dead rise). Have you ever surfed on a great wake one day and then a few days later with the same set-up had a poor surfing wake, happens to me from time to time. It would be nice to know if the attitude of the boat was different in such a case
(or if I just suck).

We've found a few inclinometers but haven't purchased any yet. The JC Whitney one looks cheesy but might be the best deal.
http://www.jcwhitney.com/autoparts/Product/tf-Browse/s-10101/Pr-p_Product.CATENTRY_ID:2008964/showCustom-0/p-2008964/N-111+10201+600002121/c-10101

https://www.imcuniverse.com/store/25cda.htm

http://www.cascadia-instrumentation.com/id53.htm

A more precise multi-axis inclinometer could be made from a Micro-Electro-Mechanical System (MEMS) accelerometer. Analog Devices make a number of precision MEMS accelerometers that can be used to measure pitch and yaw. I think that something like this could be readily integrated in to an advanced dash like the new Malibu dash.

I don’t know how many of us would spend the money on these tools. You could do a home brew inclinometer with a spirit level and compass, and a weighted string.

The question was posed over at Tigeowners.com, of having some device that would adjust ballast to achieve a preset yaw and pitch setting, once the optimal numbers were determined and recorded. Someone referenced a device used on RV's that aided or automatically leveled them once parked. Is there such a device?

I'd buy a system that did something like that so that I didn't have to mess with re-adjusting after I loaded people or different sets of folks on board.

Thanks Ed for the links. So much for my "good way to calculate" the slope. Just buy a cheap device that I didn't know existed! A tiltmeter! I'll buy me one. In the meantime, has anyone out there ever measured the swim deck tilt, after producing an exceptional wave? I'd like to know what the "recommended tilt" is.

Hi Jeff. That's a great idea, automated pitch and yaw. One more feature to add to our "wish list".

To automate pitch and yaw; a sensor is needed. A MEMS accelerometer could be that sensor providing pitch and yaw data. If you know what pitch and yaw you desire then a controller could calculate the difference between desired pitch and yaw and actual pitch and yaw. If you have an under the hull ballast fill point and a positive displacement pump the controller could automatically pump in and out ballast from/to port, starboard, center, and front tanks.

Another idea would be to weight the boat and use trim devices: steerable rear tracking fin for roll (yaw is rotation about the vertical axis), bennet tab for pitch which a computer could adjust on the fly to keep the boat at the desired running attitude-much faster than pumping water around.
As to manufacturers putting trim tanks on their boats. I am prepared to bet a very large sum that by the 07-08 model line we will see this. I'm serious, anyone want to take that bet?

(Message edited by mars on August 17, 2006)

Do trimtabs and/or wakeplates create more turbulence in the immediate area behind the boat where we are trying to create a clean wakesurf? Ed, Jeff, Cranky - what are your thoughts?

I think most of us surf with the wake plate up. I do set the wake plate down for a better goofy wake. I think that by the time the wake (water) travels a few feet back most of any wake plate disturbance settles out. However, behind my boat you can see three planar streams coming together at a point behind the boat. Under the wrong conditions these streams produce a vertical plume that sprays up in to your face. Jeff has noted a similar problem with Switch Blade enhanced wakes.

Jeff and I have noticed a middle feature in several wakes. The middle feature is a seam between two surfaces on the surfing wake. We’ve seen this middle feature on my ’04 Lightning, the Epic, and I’ve recently seen it on a VLX wake. We think the middle feature generated from the bottom and side surfaces of the boat hull, right Jeff? At higher speeds the middle feature tends to fade away. I don’t think that the middle feature is necessarily bad, but I ride mostly on my wake, so my experience is limited (it would be interesting to ride an Enzo wake).

VLX Wake

Lightning Wake

I think most of us surf with the wake plate up. I do set the wake plate down for a better goofy wake. I think that by the time the wake (water) travels a few feet back most of any wake plate disturbance settles out. However, behind my boat you can see three planar streams coming together at a point behind the boat. Under the wrong conditions these streams produce a vertical plume that sprays up in to your face. Jeff has noted a similar problem with Switch Blade enhanced wakes.

Jeff and I have noticed a middle feature in several wakes. The middle feature is a seam between two surfaces on the surfing wake. We’ve seen this middle feature on my ’04 Lightning, the Epic, and I’ve recently seen it on a VLX wake. We think the middle feature generated from the bottom and side surfaces of the boat hull, right Jeff? At higher speeds the middle feature tends to fade away. I don’t think that the middle feature is necessarily bad, but I ride mostly on my wake, so my experience is limited (it would be interesting to ride an Enzo wake).

VLX Wake

Lightning Wake

hmmmm. the gentleman from wakesurf mag. has three trimplates on his boat. I am sure that he has found some reason for having them. Some riders have claimed that his Calabria wake was one of the best they have ridden behind. Even better than the Enzo. So it stands to reason, that they do serve some purpose. Bigshow, I have had days on my boat where the surfwake is awesome (Sacriver)and then with the same setup (on the delta) we could not get any decent wake. Even though Jerry Price of Shred Stix was able to ride like a madman, it did not have the push that it normaly does. So the "Wave" can be a curious thing!

depth of water under keel or a narrow channel will affect size and character of wake also.