Custom Surf Platform build

[trayson]

I thought I'd post a formal thread on this project.

My buddy "Phathom" (Desi) is doing the work, and together we've been doing lots of planning and measurements. Our objectives have been to get something with a SMOOTH bottom that doesn't have a huge lip that digs into our surf wave. We also wanted something that was as narrow as possible relative to the surf wave without changing the platform bracket location. We chose to add a little length to it to make it more user friendly.

Here's how it's looking so far:

Still have to sand down more(possibly) and coat the bottom. It's all cut, sanded and coated on the top. It is measuring 62" at transom, 14.5" deep the brackets, 13 3/4" long angled transition, and a 43" wide platform end that measures about 23 7/8" long transom to platform end all at 7/8" thick.

It's made out of two pieces of plywood sandwiched together, because that's the wood we had laying around. Spray on undercoating to cover it, again because we had it laying around. If we like it, we'll make one out of a single thicker piece of wood, glass in the wood and put some closed cell foam decking pad on it.

My outer brackets were pretty wide, so we did what we could on width as I didn't have much of an interest in moving them or making new ones. (thanks for the welding offers though). I should have to cut off about 1.5" of the extisting outer brackets though. But it's the flat bar before the angle brace comes in, so it shouldn't affect things much. Not sure if we'll have to shim the new platform up or if it'll be thick enough to match the height of the existing as is.



I did a drawing of the dimensions. The platform brackets are in orange. they overlap our platform a tiny bit on the sides, but should we go with a full blown version, it'll be easy enough to chop 1.5" off the ends of the brackets that extend past the angle brace as mentioned above.



Pictures of the OEM Platform for reference:

[trayson]

More pics of the OEM platform

[trayson]

Oh, and this pic shows where the water line was and how the platform was cutting into our surf wave.



I have a video that shows the platform. I had to upload it to youtube because the site I had it on before isn't working. The link will be:
http://youtu.be/36X8WtKvCm8

[trayson]

Build Pics

[trayson]

Comparison Pics

[trayson]

Installed last night for prototype testing today

[phathom]

Just for the record, yes we know it is OSB, not traditional plywood, and yes we know that the dual 7/16" layers will separate over time, and yes we know that just the undercoating will not prevent this or 100% stop the moisture.
This is just to test and finish the season out to see if we should pursue a more expensive single sheet marine plywood fiberglassed version with pad and probably grab rails.
If we do make that, we figure we will have materials enough to make two, so one will most likely end up for sale on here for anyone who likes the idea and wants one too without the labor.
I am currently waiting at the boat ramp for Trayson to get here to test this sumbyatch out and here he is posting a build thread lol.
Will post pics of the results of todays testing soon... If he gets here before dark.

[trayson]

Test was successful. Only the tip of the corner was in the water and there was little to NO interference with the surf wave. The brackets being a little in the water is unavoidable and any turbulance from that seems to be going straight into the prop wash.

Bottom line is that the new platform did NOT interfere with the surf wave and we felt like we had an increase in push and maybe even a little more pocket. I forgot my waterproof cam, so I couldn't post any vid looking at the boat from the surfer's point of view. But we got as good of pics as we could from the back of the boat.

As soon as Desi gets them uploaded, we'll share them here.

At rest in semi rough water:

[phathom]

So tonight we ran the same weighting we did with the exception of moving the 150 from the rear center seat to on top of the tube sack in front of the 750. Basically moving one person to the observer seat instead of the doghouse. This balanced out us having someone in the rear seat for pictures and rope duty instead of having the bag and a person behind the doghouse, so pretty much the same type of setup we have run before.

I could definitely tell the difference in how long the pocket was and how much push the wave had. This was definitely due to the fact that the new platform sits different.
The new platform sits the same vertical height as the old platform, however it is technically higher because it is a solid, smooth bottom platform that is only on the brackets, whereas the OEM platform sits on the brackets and has a lip around it that extends about 2" from the top of the platform. So in essence, this design "raised" the platform 2" out of the water all across the board.
It also is about a foot shorter over all from side to side, so the sides do not dig into the wake and act as trim tabs. In fact, even though Trayson said the tip of the platform touched the water, in the video I am posting and in the pics you can see that none of the platform touches the water at all while at surf speed. It is truly an "unaffected ride" platform, no trademark infringement implied, it just literally doesn't affect the ride.

I have surfed this boat all summer and can easily say that this was the best wave it has ever put out. The pocket was longer and it had more push. Normally, being a bigger guy I had struggled to stay in the pocket and typically had to be really forward on the board. Tonight I had no problem staying in the pocket, my foot positioning was normal and I had to actually put on the brakes quite a bit to keep off the platform I had so much push I haven't experienced on this boat before. I had plenty of pocket to play around in and do some carving up and down the wake. I was able to do a few floaters to the back of the wave, drop down to the flats and just let the wave push me back to the front of the pocket. Something I have previously had a very difficult time doing.

The only other boat I have surfed is a 2012 Wakesetter VLX loaded up with at least twice the ballast as the Supra. While this wake did not have as much push as that, it was comparable. If I had to compare the two, I'd have to guestimate the Supra had about 75% as much push. I was able to ride the same way and play around on the Supra as I do on the wakesetter. This was a welcome surprise, considering normally I had to fight to stay in the pocket to even freeride the Supra.

With this good experience today, we are ruling it as a great success. We will definitely be moving forward with making the final version in the off season.
The only thing we noticed that might be negative is that with the "raised' platform, and it being flat, without a lip, there was more noticable exhaust coming from under the platform. Normally it would get caught in the lip and slowly escape when it built up or escape all at once when you turned the right way or stopped. A FAE build will definitely be in the future as well.

Enough talk, here are some pics, and some videos.

Rear/Side View:
Looks pretty stealth
Side View:

At speed, notice no contact with the water:

The edge and corner, also not contacting the water:

[phathom]

The wave without the 150 filled (1300 lbs of ballast), notice the visible exhaust:

Platform at rest weighted:

The wave with the 150 filled, not a big change between 1300 and 1450lbs of ballast: