What is the perfect wake? Any Help Is Appriciated!

[RADAR39]

hello to all, i am new to the ball of spray waterskiing forum however as a part of a school research project, I have decided to look into what the perfect wake looks like, as well as what are the main aspects of a boat that have an impact on how this perfect wake is created (eg, weight of boat, prop wash, speed)

You can talk of:

 

Your boat of choice,

How a top class wake has improved your skiing performance,

How to professionally analyse a wake yourself looking for certain features,

Your personal opinion of what the perfect wake is,

What design features in a boat affect its wake,

Any information or opinions you may have that could be of any relation to my research question,

Or simply I would love to hear of your perfect pass that will last a lifetime.

 

I am more than happy to answer any questions you may have about my research project, or just my skiing in general,

ANY INFORMATION IS VALUABLE TO ME AND MY RESEARCH PROJECT

 

Thankyou for your time!

[TallSkinnyGuy]

The less you feel the wake and the zone around the wake when crossing it the more perfect it is. Flat, small (i.e. low) and soft.

[dchristman]

The perfect wake for slalom or jump is no wake at all ... everything else is a compromise. It seems newer "3-event" boats aspire to achieve this.

 

The perfect wake for tricks is symmetrical, sharp, with an adequate size turbulence free table in the center for surface tricks. The balancing forces (transferred through dollars) of boat makers, slalom skiers, jump skiers, and trick skiers, do not favor the trick skier :-(. ... but I will persevere.

[madcityskier]

Best wake is cable, but the upward pull is counterproductive in it's own right.

 

[wskierman8]

Slalom skiing has been trending towards larger, wider boats. ie the SN 200 and the new MC prostar. (Both 20' long aprox 8' wide.) The reason these larger boats are providing an advantage is because they have a lower density than the older SN 196's and MC 197's. (proven by the new boats having higher weights while maintaining the same 22" draft.)

What this lower density has done is made the wakes flatter, wider and softer than what they were. Personally I still give the 200 wake a slight advantage over the new prostar but it is really close.

 

These comments are only directed towards slalom skiing at 34/36 mph as that is what I am most familiar with.

 

Some other factors that affect the wake include rpm, 3 blade vs 4 blade prop, weight in the boat (the wake tends to be harder when you have 3 fat guys in the boat vs 1 skinny driver. This goes back to my density argument.), and one last thing is that you want to make sure the boat is balanced. If the boat is tilted one way or another, the wake will also be tilted one way or another.

 

[andjules]

The basics become pretty obvious fairly quickly; compared to non-ski boats, ski boats typically:

- have a relatively shallow deadrise angle at the stern, so that the rear of the boat doesn't sink to deeply, which would increase displacement, increasing wake. So, typically: somewhat flat-bottomed, towards the rear of the boat (compared to an offshore boat designed to cut through waves; but not completely flat-bottomed like a Florida swamp boat, that would skid and get pulled from side to side)

- up until the mid-90s, the desire to have a small slalom wake was balanced against the desire to have a good trick wake. I think the rise of wakeboarding made boat companies look more closely at their demographics, and I think they started to realize that the market was not too concerned with tricks. Similarly, wakeboarding boat design began to influence ski boat design and as such (and as @wskierman8 has pointed out), the trend over the last 15+ years has been towards wider boats which—like a shallow deadrise—distributes the boat's mass in a way that makes it displace less deeply.

- Again, keeping the rear of the boat from sinking to deeply seems to be key, as the boat industry has not been able to build a truly successful V-drive ski boat (v-drives allow for a much nicer interior layout, so they'd sell like hotcakes if they could produce a wake as nice as a direct drive).

 

One wake quality that I find interesting/mysterious is 'softness':

- as mentioned above, prop choice can have a significant effect on softness

- some boats can have dimensionally small wakes but still have a 'harder' feeling wake than a dimensionally larger wake

- An interesting data point: in 1993, Malibu first introduced their S23 hull (while it has been refined, the basic shape has been used for a long time). In 1998, they introduced a variant called the 'diamond hull', which was pretty much the same hull, but with a little 'lifting' rail/strake down the outsides of the hull. You can see the difference here:

http://www.themalibucrew.com/forums/index.php?/page/articles.html/_/diamond-vs-wake-hull-r9

- - I used to own a Malibu Sportster LX, which was on the original S23 hull. It was a smaller boat, 2500lbs or less. Small wake... but a little bit of a 'hard' wake.

- - I've also owned both a Response LX and Sunsetter LXI of similar era (1998-2003), both of which were on the 'diamond hull' version of the S23 wake. These boats were 2800-3000bs, had dimensionally similar wakes—possibly a touch bigger than the Sportster's—but are notably 'softer'.

[DW]

@Radar39: great project, what is the class & what level of research / analysis are you looking for? How deep technically do you need to dive?

 

As for some of your questions - the "perfect" slalom wake would be one that does not alter the skiers ideal path cross course from buoy to buoy due to the disturbance caused by the boat wake, and if you wanted to go a little farther, one that helps create a scenario that improves the skiers angle/speed or ultimately score. Trick wake aspects would be different as the wake is used to assist the scored moves and for barefooting there are scoring and trick implications. Jumping would be similar to slalom where the least disturbance is desired.

 

The design features that create the ideal wake are many, all the hull parameters including deadrise, chines, hook, etc. all have significant effects on various portions of the wake and different effects at different speeds and line lengths. It takes a lot of compromising to get the best from 75' down to 43' off. In addition, total boat weight, balance, center of gravity, center of pressure, boat width, unit loading, spray, prop and rudder wash all affect the wake and need to be tuned as system to create the final result.

 

There is a lot to professionally analyzing a wake, including visual analysis, parameter measurements (such as table height, trough depth and width, table aeration, etc.), skier feedback, scale water tunnel, and eventually CFD analysis.

 

Good luck, I would be interested in your results & report.

[eleeski]

Slalom and jump wakes, trick wakes, wakeboard wakes, barefoot wakes and surf wakes all have very different requirements. The boat that can morph the wake to optimize all of these has not been built yet (I'm working on it).

 

You did ask our opinions on favorite boats. It's no secret that I like the MC197 as it has a great balance between all the competing demands. It led me to great slalom and trick performances.

 

Specific features are relevant only in the overall synergy of the final boat. There are so many variables that one boat's critical feature doesn't do anything to another. Experimentation and innovation are key to make the best wakes.

 

Eric

[andjules]

Boat designers obviously have to balance a lot of objectives; one obvious objective that hasn't been mentioned is tracking (vs wakes).

There are lots of boats with smaller wakes than a direct drive ski boat. But typically, they aren't very capable of holding a straight line or a constant speed as the skier exerts forces on it. A light-weight 90hp outboard on a flat-bottomed speed boat could have a great wake at 34/36 but it wouldn't drive straight. Designing a ski boat to have small wakes is a lot like designing a tractor-trailer to be aerodynamic - you can't really make it materially smaller or less powerful to achieve your objective - you'd be missing the point.

[ALPJr]

Ask @kpickett for a picture of his '93 MC wake at 34mph. Perfection

[GOODESkier]

Two points.....

 

1. At 34.2 and 36 MPH and 28' OFF and shorter, all wakes are created equal in my opinion. If I closed my eyes, any of the 4 slalom tugs out there and many previous models are all the same in my book.... to a point.

 

2. Now, at 15.5 MPH Long Line with my 6 year old swerving around buoys, he will be the first to tell you the MASTERCRAFT PROSTAR is straight up, his favorite boat. I am a NAUTIQUE GUY, so for me to say this....... it must be true! In order for any other boat to have the same SMALLER wakes of the Mastercraft at 15.5 MPH the other boats have to be going 17 or 19 MPH to get the same smaller size of the MC. Just how it is. I have spent the entire summer observing this as we did tournaments and practiced all over Washington State. While I like the Malibu, it has the worse wake of all manufacturers at 15.5 MPH. My son can run 21 MPH behind the MC and struggles to run 19 MPH on the Malibu.

 

All just my undocumented and unscientific observations as a Dad of my 6 year old swerver!

[fox197]

Interesting study. I'm not familiar with what difference a 4 blade to 3 blade would make. Can someone shed some light on that for me. And I believe @MarcusBrown had a fair bit to do with the engineering of the new prostar so you could get in contact with him for a lot of details

[RADAR39]

@DW: The more indepth information the better, the outcome (where you answer the question) is around 2000 words, therefore that is alot of room to talk about many different sub questions within the one question in a great amount of depth.

 

Thankyou for your information, it is far ahead of anything i imagined receiving and will go along way in helping me write the outcome.

[estrom]

Are you strictly concerned with wake characteristics, or are you looking at overall slalom performance which would include tracking, etc...? If you're just looking at wake shape, go find yourself an early '80's Avenger with an outboard. That was our ski tug for 20 years (no bouys around here). Tournament boats don't come close to the small size and softness of that wake. It doesn't qualify or pretend to be a tournament boat due to tracking, etc..., but the wake is phenomenal.

[A_B]

For the in laws....