How to create a smoother wake?

inthedirtagain

Petty Officer 1st Class
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Aug 10, 2011
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My family has learned to kneeboard over the last few years behind a variety of boats that I've brought home. Our current boat is a 1969 Silverline DeVille with the original Merc 1000 that we brought home with us while on vacation this summer. Its in great condition, tops out at around 36mph, and has been a reliable fishing/play boat of my grandparents since it was new. We spent about 2hrs on the water yesterday and my wife complained that it wasn't a very smooth ride while on the board. The wake produced by this boat is fat and rideable for an OB boat and provides a great "pop," although none of us are very good at kneeboarding yet.

When I was on the board, I noticed that the area immediately behind the boat and between the largest part of the wake (where we like to ride) has many surface irregularities that makes for a rough ride. Our previous boat was a much heavier Invader sterndrive (2100 lbs vs 1200 lbs) that had a smoother wake. That boat was wider and had a deeper draft compared to the Silverline. I know that the current prop is pretty chewed up and needs to be replaced, but would this contribute to the choppy ride on the board? The water didn't appear to be rough yesterday, nor was it windy. Would some sort of Whale-Tail help? I've noticed a bit of cavitation when entering turns, so I can only imagine that the ugly prop is causing some extra airation. The cavitation plate is about 1/2 in above the bottom of the boat, so I don't believe that raising or lowering the OB is going to make things better. Everything is set up correctly. Your thoughts would be appreciated. Just trying to get a smoother ride.
 

H20Rat

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Mar 8, 2009
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First suggestion... Don't kneeboard behind the boat! Ideally you should spent very little time between the wakes, and if you are, you should be airborne.

Anyway, trim and loading will have a HUGE affect on the wake. Try changing trim, moving weight both forwards/backwards as well as sideways. (a leaning boat can dramatically impact the wake also.)
 

southkogs

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A wake is a product of how the hull interacts with the water ... the way you reduce the amount of wake (or at least two main ways) is 1) reduce the amount of boat in the water or 2) spread the load out over a wider surface of the water. The DeVille's hull is really designed for cruising and cuts in to the water quite a bit. If she's built like the Comoro is, she's probably a chunky-monkey for her size too, digging into the water a little deeper. My Comoro is actually a little wider than your DeVille (I think) and it still digs in and cuts a bigger wake.

Trim adjustments and maybe tabs might get you a little higher up on plane and cut the wake down a little.
 

oldjeep

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May 17, 2010
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Typically putting more weight in the front will help smooth out a wake, but that should reduce the overall wake not just smooth out the center of it.
For your purposes why not just play with the rope length and find a spot that you deem acceptable?
 
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Texasmark

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Dec 20, 2005
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Agree with the above.

Course on the prop being chewed up, it may be the source of your ventilation (cavitation) or engine mounting height, or hull variations preceding the lower unit or trim position....farther out the more prone it is to ventilate in rough water or pulling heavy loads.

Think about the different wakes you have experienced for example when a heavy cruiser came by you and a 14' alum boat with one kid in it traveling at the same speed. Think about the wake size of your boat just before planing and the wake after you get up to speed. Supports the comments above.

I think you are on the right track with a Whale Tail to get the transom up and reduce the wake. And you don't want a prop with a "high rake" like you see on Bass Boats. Conventional alum prop with blades sticking straight out rather than folded back (raked).

My 2c,
Mark
 

inthedirtagain

Petty Officer 1st Class
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Aug 10, 2011
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I appreciate the comments. Just to be clear, we're happy with the size of the wake. I was actually surprised that this 16ft Silverline could produce such a fat wake since its pretty light and also has a narrow beam. I've played around with the trim settings and found that 3 holes out lifts the bow out of the water just fine, but blows the prop in turns at speed. My grandfather had the trim all the way against the transom, so when I took it out the first time, the wake was large, but the boat ride was really choppy and rough. I trim'd it out and found that the boat would pick up speed and smooth out, but couldn't hold it when turning. 2 holes out is the best position for ride/speed, but now I need to deal with the rough water between the wakes. I've thought about adjusting the length of the rope, but then we'd be out of the "sweet spot" of the wake. Obviously, I've got some more testing to do. My first plan of action is to replace the prop and go from there. This thing is so beat, I'm sure that its got to be contributing to the water surface behind the boat, if not just hurting performance. Will report back soon. Thanks again for all the suggestions.
 

Texasmark

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Dec 20, 2005
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Doubt you will rid yourself of the "prop wash". The wash is actually the result of prop slip pushing water out that didn't result in the boat moving forward. Were it not for that there would be essentially no turbulence other than exhaust bubbles. When we were in the arena, I think ski ropes were 100'. I can recall when at times, for fun, I would pull myself forward on the rope and yes the wash gave you a little pitter patter on the bottom of the ski. But I quickly realized that I shouldn't be doing that because if I became entangled in the rope and fell It could disjoint me or worse.

Mark
 

gddavid

Petty Officer 2nd Class
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Jan 4, 2010
Messages
193
The prop isn't very deep on that boat because of the boat's size and weight. Lowering the mounting position of the outboard may help but may not be an easy option and it is very unlikely to be worth the effort, it would also hurt you speed and possibly lead to porpoising. A larger diameter prop in a smaller pitch may help slightly but probably not worth the expense. I agree with staying outside the wake and/or playing with line length.
 
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