Bayliner 4788 Stabilization

[ksanders]

Here is the nose.

[talman]

Looking pretty beefy! Questions: How did you determine the angle of the fins relative to the boat. At hull speed, pretty easy to determine, but what about when on plane? Might they provide some lift to the arse-end and improve speed, or will the added drag negate any potential increase? I know most of this is theoretical until you get her on the water, but I was curious about the performance other than at hull speed. Maybe you are content to be at hull speed, like most of your journey south? Best of luck getting splashed and exploring the "new" boat.

[SteveK]

Well, whether they work or not, the progress pictures showed a professional job being done.
Just now looking at the sanding and seeing they are still smoothing it out, the missing brown on the light spots. It does look like they were factory installed.

[ksanders]

Looking pretty beefy! Questions: How did you determine the angle of the fins relative to the boat. At hull speed, pretty easy to determine, but what about when on plane? Might they provide some lift to the arse-end and improve speed, or will the added drag negate any potential increase? I know most of this is theoretical until you get her on the water, but I was curious about the performance other than at hull speed. Maybe you are content to be at hull speed, like most of your journey south? Best of luck getting splashed and exploring the "new" boat.

You are correct everything is pure speculation until launch day.

We went with 45 degrees, simply because others had done the same.

We went with 12" because the material we vbought came in 12" strips and when I was asked 12" sounded good.

We went with 4" thick at the base and 2" at the tip because that made sense since the material is 1" thick.

This shoot from the hip idea of rolling chocks design is probably the reason people shy away from them.
If you think about it, there is no money in these for R&D. This is boat yard work.

We know rolling chocks work, and there has been a bit of design work done, but not a lot.
How much they work, only time will tell.

[talman]

I was more thinking of the angle running stern to bow. At hull speed, it would match the waterline, all good. But what if at plane, it gave some lift of the back end. That might be really good?

[ksanders]

I was more thinking of the angle running stern to bow. At hull speed, it would match the waterline, all good. But what if at plane, it gave some lift of the back end. That might be really good?

I suppose any lift at planing speed would be a benefit. Less tab down?

We're going to have to find out.

[ksanders]

Well, whether they work or not, the progress pictures showed a professional job being done.
Just now looking at the sanding and seeing they are still smoothing it out, the missing brown on the light spots. It does look like they were factory installed.

Yes, that is true. if they don't work at least they will be a conversation starter

[Jim_Gandee]

The final determination of the chocks performance will be very subjective as how does one actually measure that kind of performance? That said, how could they not help with roll? They gotta do something! For the cost I think the experiment would be worth it! Can’t wait to hear the final verdict! Also, it’d be really interesting to see how the shape of the chocks would affect performance. What if they had a camber, like an airfoil? I’ll bet a CAD program would help answer those questions.

[ksanders]

Todays update...

The boat yard is going by the book on this job!

They are using interlux 2000 barrier coat. On the bare fiberglass they used one coat, then they used a west systems based faring compound.
After sanding the faring compound smooth, they are adding three more coats of barrrier coat before bottom painting. This is exactly what is called for in the Interlux techincial specification.

Based on the drying times, and remembering that they need to move the jack stands we are now anticipating launching on Friday morning.

I am happily staying on the boat. The boat yard has clean showers and I am comfortable watching the progress.

BTW... This afternoon I was curious. Do the fins stick out the side of the boat, and will they impact the dock???

The answer is no. I personally hung a weighted line a point about a foot above the waterline, (which is where a floating dock touches) and there are a couple inches of clearance at minimum, so no worries there. The clearance is tighter in the aft, and the space gets larger the more forward you go.

[[email protected]]

Looks great!

[talman]

Best pics so far! Looking good, and good luck on Friday launch

[builderdude]

Don’t most docks protrude out beyond the float system underneath a few inches? If so the new fins shouldn’t be an issue.
🤔

[SteveK]

Kevin, will you be using fenders at the dock, 6-8 inch fenders?

[ksanders]

Kevin, will you be using fenders at the dock, 6-8 inch fenders?

I typically use 10" fenders at the dock, but I do not generally deploy them until I am tied up.

The fins won't touch the dock, so I'm happy.

[tom]

Kevin, this really looks like a great job and workmanship at the yard you are using!

[Yacht Quest]

Damn that’s looking good!!!