Ok, Lets get scientific about surf wave shaping on these 19 footers

[Tlcaffall]

I just finished watching this video on you tube.

I keep reading threads where people want to know exactly how your boat is balanced and weighted to keep a rope-less push. After watching this video I think we need to get some real numbers......

The three main variables (maybe 4) we are working with are "pitch", "roll", and "draft" and maybe a wake shaper like a wakebooster.

Pitch and roll can easily be measured with an app on your phone and we should place the phone on the floor of the boat somewhere with the top of the phone toward the bow of the boat.

Using the Clinometer app that was suggested in the video I want to know:
1. What is your "Pitch" (bow / stern tilt) in degrees with boat at rest
2. What is your "roll" (port / starboard tilt) in degrees at rest (goofy or regular)
3. What is your total estimated weight in the boat including gear ballast and peoples (hopefully not over 1200 for these boats) (Draft)
4. What is your speed and is it GPS controlled
5. Water Depth
6. Are you using a wake booster yes or no
7. What year and model is your boat
6. What is the largest person you have pushed rope-less and what board were they on.


Once we know pitch roll and draft, we can move weight around the boat to match.

Ready Go......

 

[anmut]

More variables than that- off the top of my head and based on my experience:

1. Displacement
2. Transom design
3. Water depth
4. Shaper

Displacement is # 1, this creates the huge roll of water in the back of your boat. Depth of the water is just as important, as you need enough water under the boat available to rush back up to the rear of the boat after it's displaced. Anyone that's hit a "shallow spot" of 8' or less while surfing from deeper water can instantly feel the push leave the wave.

Transom design goes along with, but before, pitch and roll. Your transom will determine how the displaced water "shoots" back to the rear of the boat - does it come up suddenly or does it roll gradually. Pitch and roll of the boat are fine tuners of the transom design.

Speed is huge, and accurate speed is absolutely necessary. Surf waves are extremely sensitive to not only weight movement within the boat (why Supra has an automatic ballast system to adjust to passenger movements), but speed controls the height, length, and push you might get from a wave. Slower speeds usually net rampy waves with short pockets, faster speeds usually net smaller, yet longer pockets.

While not necessary for ropeless surfing, a shaper will give you a clean wave that a skim board needs for tricks. It can help create additional pocket length as well.

Per your questions:

1. What is your "Pitch" (bow / stern tilt) in degrees with boat at rest and at surf speed: bow up
2. What is your "roll" (port / starboard tilt) in degrees at rest and at Surf speed: pitched towards surf side
3. What is your total estimated weight in the boat including gear ballast and peoples: 2k-3k pounds
4. What is your speed and is it GPS controlled: 10.5 to 11.5mph depend on load
5. Are you using a wake booster yes or no: yes, wakebooster
6. What is the largest person you have pushed rope-less and what board were they on. 250lbs on a hybrid board
7. What year and model is your boat: 2020 212S

I will also tell you that, if you're chasing a wave like you see on a vdrive boat, you're going to be chasing that forever. Between the jets and the hull shape, those waves are near impossible to replicate. But you can score a really decent and fun wave to surf all day long on. And at the end of the day, you can beat the vdrives back to the ramp 20mph faster and don't have to worry about wrecking a $800 prop if you hit something.

 

[Tlcaffall]

My experiment on 6/2/2021:

1. Pitch Not measured or controlled
2. Roll not measured or controlled
3. Weight estimation: Full gas tank with about 900-950lbs of gear and people (no extra ballast)
4. 10.7mph gps controlled
5. Water Depth 20+
6. no wake booster
7. 2017 Ar190 (ribbon delete, lucky 13 cone, pump seal, air filter upgrade)
8. Could not push beginner 210 pound rider rope-less, but pushed a 180lb rider on foil rope-less all day.

 

[Tlcaffall]

Anmut, thank you so much for your reply. I understand these are not wake boats, but I also enjoy getting every last bit of performance I can out of a $30k package. Maybe part of it is the pleasure I got, even as a kid, when I could out jump that kid with the name brand bmx bike and I was on my crappy huffy. (PS I am also 5'7" and suffer slightly from Napoleon syndrome)

Just so we are on the same page:
1. Displacement = draft or weight
2. Transom design is very similar on these 19ft boats with slight variations depending on boat year
3. I added water depth to the list thank you.
4. Wake shaper is also included in the list.

If you get a chance I would also like to see what your exact pitch and roll are.

 

[kgower]

I just finished watching this video on you tube.

I keep reading threads where people want to know exactly how your boat is balanced and weighted to keep a rope-less push. After watching this video I think we need to get some real numbers......

The three main variables (maybe 4) we are working with are "pitch", "roll", and "draft" and maybe a wake shaper like a wakebooster.

Pitch and roll can easily be measured with an app on your phone and we should place the phone on the floor of the boat somewhere with the top of the phone toward the bow of the boat.

Using the Clinometer app that was suggested in the video I want to know:
1. What is your "Pitch" (bow / stern tilt) in degrees with boat at rest
2. What is your "roll" (port / starboard tilt) in degrees at rest (goofy or regular)
3. What is your total estimated weight in the boat including gear ballast and peoples (hopefully not over 1200 for these boats) (Draft)
4. What is your speed and is it GPS controlled
5. Water Depth
6. Are you using a wake booster yes or no
7. What year and model is your boat
6. What is the largest person you have pushed rope-less and what board were they on.


Once we know pitch roll and draft, we can move weight around the boat to match.

Ready Go......

Saw this video a few weeks ago. I thought is was pretty good. As soon as I get my boat through the break-in I'll start playing around with ballast. I have the 19' wake surf package. My initial thoughts after having watched the video is to put a bag in the ski locker a small amount of weight in the bow and some additional weight on the surf side

 

[Scottintexas]

8. Could not push beginner 210 pound rider rope-less, but pushed a 180lb rider on foil rope-less all day.

probably one of the most important parts of the equation is what board and what level of ability the rider has,
it took me almost 30 sessions to figure out how to go without the rope
with the same wave I can now ride all over it without the rope for extended periods,


.

 

[anmut]

probably one of the most important parts of the equation is what board and what level of ability the rider has,
it took me almost 30 sessions to figure out how to go without the rope
with the same wave I can now ride all over it without the rope for extended periods,


.

Lots of truth to this - if you're leaning on your back foot surfing and applying gas, no matter what the wave, you'll never drop the rope. A good technique is to hold onto the rope and just put your arms out in front of you like superman. It'll automatically shift your weight forward and suddenly you'll be like "holy sh*t I'm going to ram the boat!"

 

[anmut]

Anmut, thank you so much for your reply. I understand these are not wake boats, but I also enjoy getting every last bit of performance I can out of a $30k package. Maybe part of it is the pleasure I got, even as a kid, when I could out jump that kid with the name brand bmx bike and I was on my crappy huffy. (PS I am also 5'7" and suffer slightly from Napoleon syndrome)

Just so we are on the same page:
1. Displacement = draft or weight
2. Transom design is very similar on these 19ft boats with slight variations depending on boat year
3. I added water depth to the list thank you.
4. Wake shaper is also included in the list.

If you get a chance I would also like to see what your exact pitch and roll are.

Just so we are on the same page:
1. Displacement = draft or weight Both. Draft gets you in the water, weight gets you further in the water. You want to displace as much water as you can without sinking.
2. Transom design is very similar on these 19ft boats with slight variations depending on boat year Agreed. Unfortunately, jet boat transoms don't have the steepness to really purge the water in volume and as suddenly as a vdrive. We also have the stupid jets doing their best to push that water out faster than you optimally want too.
3. I added water depth to the list thank you. Water depth is a big deal!
4. Wake shaper is also included in the list.

Tomorrow when we go out, I'm going to setup, and take pictures, of my boat in the various stages of ballast - should give a good visual of how weight and speed impact wave quality.

 

[kgower]

Any updates to be shared? This year I'm going to move both 200lb sacs to the surfside and put a 365lb sac in the ski locker. Pretty confident this will make a difference.

 

[anmut]

Those 200lbs sacks won't do much - invest in the transom sack to really lower that boat. Goal is to have the rear deck underwater.

 

[Tlcaffall]

I have the transom sack. I can go rope-less with a 650lb transom sack in the middle (I have half my family regular and half goofy foot so I can't dedicate a sack to one side). I have about 240lb of sand bags that I can put on one side or the other to adjust the wave. I also usually have about 6 people in the boat that I can move around. My biggest variable in this set up is elevation. I have the ar190 and I can get to 10.2mph at my local lake (about 1500ft elevation). I can't get up to speed at Lake Powell 3500ft elevation. I have decided to just learn to Foil. I don't have to set up the ballast and it is way funner for me anyhow.

 

[anmut]

That is AWESOME and now, my new goal for summer 2023.

 

[kgower]

I have the transom sack. I can go rope-less with a 650lb transom sack in the middle (I have half my family regular and half goofy foot so I can't dedicate a sack to one side). I have about 240lb of sand bags that I can put on one side or the other to adjust the wave. I also usually have about 6 people in the boat that I can move around. My biggest variable in this set up is elevation. I have the ar190 and I can get to 10.2mph at my local lake (about 1500ft elevation). I can't get up to speed at Lake Powell 3500ft elevation. I have decided to just learn to Foil. I don't have to set up the ballast and it is way funner for me anyhow.

How does the boat handle with the weight load? I'm guessing at the weight of the 6 passengers, let's say 175lbs = 1050 plus (fat sac & sandbags) 890lbs, which puts you 340lbs over capacity, before gas, equipment et cetera.

 

[Farny]

How does the boat handle with the weight load? I'm guessing at the weight of the 6 passengers, let's say 175lbs = 1050 plus (fat sac & sandbags) 890lbs, which puts you 340lbs over capacity, before gas, equipment et cetera.

Our setup is right at capacity weight - 650lb transom bag a MUST. Beyond that we adjust # cube sacks filled (2) 300lb, and move them based on how many and where passengers are located. Found we need weight toward the bow (either passenger or cube) to eliminate cavitation. We have a pretty cool “auto ballast adjust system” (unpopular captain shouts orders to the crew).

As far as handling -fully loaded the boat is working at over 6k rpm to maintain the ideal 10.5 mph for surfing our boats. Steering is no issue. Have to say crossing wakes and wind are something we fight though.

at the end of the day our boats aren’t dedicated surf boats and will never perform as such, but they are fun and are definitely surfable ropeless for up to 250lb surfer. I’m shopping surf boats now but want to keep the 195s as well

 

[kgower]

Our setup is right at capacity weight - 650lb transom bag a MUST. Beyond that we adjust # cube sacks filled (2) 300lb, and move them based on how many and where passengers are located. Found we need weight toward the bow (either passenger or cube) to eliminate cavitation. We have a pretty cool “auto ballast adjust system” (unpopular captain shouts orders to the crew).

As far as handling -fully loaded the boat is working at over 6k rpm to maintain the ideal 10.5 mph for surfing our boats. Steering is no issue. Have to say crossing wakes and wind are something we fight though.

at the end of the day our boats aren’t dedicated surf boats and will never perform as such, but they are fun and are definitely surfable ropeless for up to 250lb surfer. I’m shopping surf boats now but want to keep the 195s as well

I have the same proprietary auto adjust ballast system, it works wonders.

 

[Tlcaffall]

We are probably over loaded with that set up. Four of the six are kids/teenagers 110lb or less. the boat steers fine, I just cant get up to speed very good the more weight I add. I have a DIY wake shaper, but that just makes it even harder to get to speed.