Boat Length and Weight

[slalomjunkie]

I have a few questions about boat length and weights with regards to depth, draft, wake, wake shape and shoreline effect.

1. I have been told in the past that water depth affects surf wakes – is this true?

2. What is the minimum depth needed for a good surf wake?

3. Anyone on a private lake: What your rules for boat sizes – length, weight?

4. Is there a significant difference in draft between a 3500 lb boat and a 4000 lb boat?

5. Does anyone think that raising the boat weight limit (not length) from 3500 to 4000 will have a significant negative shoreline effect?

Thanks in advance guys

[willyt]

1. Yes, absolutely

2. The deeper the better, but I would probably say 10 ft

3.im not on a private lake

4. All depends on the hull design and length. If you took the same wakeboat and added 500lbs to it, might affect the draft, .5-1 inch maybe?

5. Is ballast illegal? Because if not, this question makes absolutely no sense

[slalomjunkie]

1. Yes, absolutely

2. The deeper the better, but I would probably say 10 ft

3.im not on a private lake

4. All depends on the hull design and length. If you took the same wakeboat and added 500lbs to it, might affect the draft, .5-1 inch maybe?

5. Is ballast illegal? Because if not, this question makes absolutely no sense

Thanks for the reply.

Ballast is legal, what I was referring to as dry weight. In other words, how different would a ballasted 3500# boat be vs a 4000# similarly ballasted boat?

Our lakes are max 6 ft deep, which is probably why noone surfs. But it is possible the boat size restrictions are about to change.

[LDA6339]

1. I have been told in the past that water depth affects surf wakes – is this true?

Buy in large, yes. How much it effects it depends on the type of device being used to create the surf wave. Side deploying devices will effect it less than downwards deploying devices.

2. What is the minimum depth needed for a good surf wake?

15ft for a Gen2 style system.

3. Anyone on a private lake: What your rules for boat sizes – length, weight?

4. Is there a significant difference in draft between a 3500 lb boat and a 4000 lb boat?

Not an expert but I doubt it

5. Does anyone think that raising the boat weight limit (not length) from 3500 to 4000 will have a significant negative shoreline effect?

Not an expert but I doubt it

Answers in red.

[jkski]

Speaking solely to shoreline impact:
Regardless of boat size, weight, the larger the wake you create, the bigger impact it will have on the shoreline. Slalom boat wakes at 34-36 tend to roll up gently on the shoreline but take that same slalom boat and slow it to 15mph and watch the difference the wave action has as it crashes in on the shoreline causing a digging effect. This is not to say that you should ban any such action, it solely means that you will need to plan for shoreline erosion and guard it accordingly. Pure sand shorelines with a 10:1 slope will get eaten up quickly but let the reeds grow up or put down some sizable stone to absorb the wave action and you will save your shoreline.

[Tsumi]

A shorter/smaller boat will sink more and create a larger (taller) wake than a larger boat of the same weight in general.

[osmonet]

I have a few questions about boat length and weights with regards to depth, draft, wake, wake shape and shoreline effect.

1. I have been told in the past that water depth affects surf wakes – is this true?

2. What is the minimum depth needed for a good surf wake?

3. Anyone on a private lake: What your rules for boat sizes – length, weight?

4. Is there a significant difference in draft between a 3500 lb boat and a 4000 lb boat?

5. Does anyone think that raising the boat weight limit (not length) from 3500 to 4000 will have a significant negative shoreline effect?

Thanks in advance guys

1. yes

2. About 10ft.....we are 6-8 feet on our lake and cant get a good wake to form

3. No rules on our private lake. Only limited by ramp access and navigation

4. Not and expert, I think it would greatly depend on the hull shape

5. Not and expert but, I think this is a wave energy question which is caused by several factors. I don't think that weight of the boat can be correlated to larger wave without taking other factors into account.

Side note....on our lake people are always worried about shoreline erosion, only half are willing to spend money for riprap or other measures to control it. Its easier to complain about activities of others than to take charge and fix your situation /end rant.

[slalomjunkie]

Interesting points...

@jkski - are you suggesting that the trick wake of a D Drive tourney boat would be similar on effect as a v drive ballasted wake boat in terms of shoreline effect?

[slalomjunkie]

Side note....on our lake people are always worried about shoreline erosion, only half are willing to spend money for riprap or other measures to control it. Its easier to complain about activities of others than to take charge and fix your situation /end rant.

I get that and 10s of 1000s of dollars have been spent on rip rap both @ homeowners personal expense and at the HoA. The think I think that has people concerned is the inevitable fact that one day he lakes will have o be drained and dredged.

[Loewen]

A 16' bayliner will erode your shoreline if driven around the lake at 8 mph

[jkski]

Interesting points...

@jkski - are you suggesting that the trick wake of a D Drive tourney boat would be similar on effect as a v drive ballasted wake boat in terms of shoreline effect?

The trick wake would be OK as those are typically in the 15-20mph range but take any DD boat and run it at 8-12mph (mushing) and look at the swell that forms behind it. Most certainly not as bad as a v-drive doing the same or weighted but far larger than your on plane slalom wake. The purpose built private lakes are mostly narrow and the larger waves just do not have a chance to lose any of their energy before hitting shore. It's going to take a while to see the impact on the shoreline of a DD boat that is mushing but a weighted V-drive will have your HOA expenses rising in hurry for shoreline repair.

[slalomjunkie]

The purpose built private lakes are mostly narrow and the larger waves just do not have a chance to lose any of their energy before hitting shore. It's going to take a while to see the impact on the shoreline of a DD boat that is mushing but a weighted V-drive will have your HOA expenses rising in hurry for shoreline repair.

Thanks!

[osmonet]

I get that and 10s of 1000s of dollars have been spent on rip rap both @ homeowners personal expense and at the HoA. The think I think that has people concerned is the inevitable fact that one day he lakes will have o be drained and dredged.

In MN, DNR is scheduled to make some recommendations to the state legislature in the 2021 session about a similar topic on smaller lakes and surf boats

https://www.minnpost.com/environment/2020/03/the-battle-over-wake-surfing-has-made-its-way-to-the-minnesota-legislature/

For what its worth, I keep coming across the 200ft number when researching this topic. Seems there is some controversial research that says wave energy dissipates significantly after 200ft.......I suppose for a narrow man made HOA lakes, this is of little help.

Also, I didn't mean to imply that your situation was similar to my rant. Good luck