2018 GS20 Help Dialing in Surf Wave

[CVAGS20]

We just picked up a 2018 GS20 and are trying to dial in the surf wave. I have searched and read all the posts here regarding setting up the boat for the "best" wave, however, many of the posts are a number of years old and there seems to be conflicting views regarding the ideal speed and weight. Now that the boat has been out six years, I'm hoping that there may be some new information available. I realize there are going to be a number of people that are going to say that this hull cannot produce a decent surf wave, however, I'd like to keep this thread constructive and focus on getting the best possible wave with what we have.

To provide some background, the boat has a ZZ4 engine and I just installed Wavemaker 620 lb piggyback bags in each of the rear lockers (we have not been out since they were installed). We are at sea level and it is usually just my wife and I in the boat towing one another. I'm 190# and she's 130# and we both ride goofy. She has a H/L Shim and I have a Liquidforce Space Pod. Using the factory ballast and surf settings, my wife has been able to ride both boards without an issue, however, I have only been able to successfully ride her Shim in a very small pocket close to the transom. Currently, besides having a small pocket, the wave has very little push.

As I read that, due to the GS20's unique hull design setting up the boat is different than other Nautiques, any help or insight on what has worked for people with a GS20 would be greatly appreciated. I have considered additional bow weight (if necessary) and even running a suck gate if that will help. This is our third tow boat but our first Nautique. We love the boat, but would like a better surf wave. Thanks in advance for any advice.

[Scooter G]

Congrats on the new GS CVAGS20, I think they are a sexy looking boat. It will take someone with a dialed in wave on a GS to polish this up for me, but I'll throw in my 2 cents. It was a game changer for our surfing on our old Supra when we added what you call a suck gate, we called it "the block". No more listing with weight to get the wave dialed in. The bonus here is that you won't have to keep switching sides with it if you both run goofy. If we didn't have enough people in the boat for additional weight, as it sounds in your case, we had another couple of additional bags we would throw in the center, I think they were @ 250 lbs each, we called them Elmer & Delmer (we would usually only run one). The wave was actually pretty impressive, better than my Son-in-laws newer 24' Supra. You should have no problem with that boat creating a wave that will put a smile on your faces. It will just take a little extra effort, but worth it.
I got a ticket many moons ago for running without a 3rd person spotter for a quick ski run, on a dead day with next to no one on the lake. Just making a mention. And then, the best thing that ever happened, a daughter that could raise the flag starting at age just over 1 and still in diapers, lol. Nothing in the rules books on that one...

[hal2814]

There’s not a single ideal speed and settings. From what I remember in that other thread the person who ran with less than factory weight was a skimboarder and that’s a pretty common thing for skimboarders to do on a Nautique. But for the most part you need weight and a lot of it. The 620s are a good start.

Have a driver and a rider who will hold onto the rope the entire time. Fill everything to 100%. Visually inspect the new bags to make sure they’re full. Run at 11.5mph NSS 0 NCRS 5. If the wave looks washy to the driver, drop weight on the opposite side until it cleans up. That’ll give you your base wave. That’s the most push you’re going to get at that speed. If it’s still not enough push for the rider drop speed in .2 mph increments until you like it. Again, keep holding onto the rope. Just check to see if you ca. get slack in the rope from the push. If the wave got washy while dropping speed bump up NSS until it cleans back up. 1 or 2 should be enough.

That’ll be a fun wave for now but when you want to get it longer, you can lower the NCRS to do that. You will lose a little push and a little height the longer the wave gets. If you get the length and height you want but don’t have enough push, add more ballast, usually midship or in the bow. Be careful with the GS bow. It dips easily so don’t overdo weight up there.

[CVAGS20]

Scooter G - Thank you. We have had a number of boats over the year but have always wanted to own a Nautique after skiing behind one while at Rollins College back in the 1980's. Our last boat was an MB Sports 23' B52 that we had to list with a lot of weight and a suck gate. I was assuming that we would have to add additional ballast to this boat as well. Also, fortunately in Virginia we don't need a spotter and can ski/wakeboars/surf with just a driver. We were out Sunday and the States' Game and Inland Fisheries officers stopped their boat and were watching us surf until the waved and drove off.

hal2814 Thank you for the detailed step-by-step approach to dialing in the wake. This will be very helpful as I will be able share these instructions with my wife and we can both follow them to get the best settings for each of us. It should save a lot of time and frustration compared to haphazardly guessing at what tweaks to make next.

[Scooter G]

Nice, well then if you are familiar with the MB, then you got this!
Sounds like we are moving to Virginia, lol.
Let us know how it goes, no one ever gets tired of a picture and a good wave...

[Tigerxj]

on our 2017 GS20, we tried a bunch of suggestions here, and didn't have much luck, until someone suggested dropping the speed. We dropped it down to 10.5 in a custom profile setting, and I can surf that wave all day long on factory ballast. we were pretty close to pulling the trigger on additional ballast, but after doing that, we had no trouble. no we do all surf on the regular side. I'm 162-165#, my wife is 149 same height, we ride the same board.

when we first started, I tried a skimmer board, cant remember the brand/model/length. We then picked up a larger liquid force rocket, still had trouble, so we picked up a larger broadcast. Around that time, we slowed the boat down, and I can surf the rocket no problem. The Broadcast is probably too big for me, and I cant really stay on it well, unless I have one of the kids riding with me, then i can surf that all day.

I recently started trying out the skim board, and its wild, but the thing feels so much quicker than the surf-style rocket.

What I'm saying is, having never surfed before, I think a lot of the equation was my progress as a rider. I've not surfed behind anything else, but plan to with a buddie's malibu soon, but given the size, length, weight of the GS20, I think it may require a lot more active riding than a larger boat. IE, you have to surf the wave rather than just ride it. That said, as my skills have improved, I can just stand there in the pocket if I want to, but that's no fun!

[MN Ryan]

Congrats on the new GS CVAGS20
I got a ticket many moons ago for running without a 3rd person spotter for a quick ski run, on a dead day with next to no one on the lake.

Ouch! In MN, we don't need a spotter if we have a mirror.

[37tr3n5k]

What is your bow doing? If your bow is not in the water, your wave will be very short. Can you post a video of your wave from stop to showing it form and what speed you're running?

[cbeitel123]

i have a 17 GS20 and absolutely love this boat. While the surfwave is not as good as a G23, it does so many other things better (for my interests at least) and the fit and finish is the same all for around 75K to 125K cheaper. No brainer for us to stay in a GS.

Surfwave enjoyment is a function of boat setup, board (style, length and volume) and rider skill-level. We have our boat setup to where i believe our riders can do everything the bigger boats would let us do (Aerials, shove its, spins)

We run 100% ballast in all tanks (we dont have the supplemental system however). We then have 200lbs of lead in the nose compartment and then nominally 200lbs in each of the rear lockers as far back as possible and towards the ouside of the boat. When we ride Starboard we shift 200lbs of lead from the port to the starboard side.

NSS always at 0. NCRS I like at 5 (most push, however shorter wave) but my more advanced son runs at 3 (longer wave,less push). Speed is then the last variable. 11.5mph will give you the longest wave but less push. We have riders that go down to 10.8mph which would give them more push but will sacrifice length

For your situation i would start by trying to get good push until your board and skill level merits more length. Therefore run 10.8mph, NSS 0 NCRS 5, all tanks 100% full however take out 200 to 400lbs on the supplemental ballast on the opposite side (port in your case). Then i would consider buying 200-400lbs of lead to put in the bow but that will only increase length and also lower your rpms and save gas (wont improve push). We have a different prop but thats primarily to get our rpms lower and be able to run the boat at high altitude. From there add speed to increase length as your skill and boards allow.

Good luck!