Bayliner 4788 Stabilization

[RDOIII]

Re the fins and dock clearance, don't forget to consider any effects of the boat being rolled by a wake or waves.

[ksanders]

The work is done, and here is the finished product.

The Bilge keels are 12" wide and 24' long. The last two feet are tapered to a point.
They are made of fiberglass reinforced coosa board 2" thick on the outside and 4" thick at the hull.
Over 40 gallons of west systems resin were used in the construction.

Tomorrow they will move the jack stands and apply bottom paint in those small areas.

Launch is Friday morning.

The functionality of these is for the most part going to be a subjective determination except...

Right before I left my dock for the boat yard I recorded a video of me causing a roll in the boat by repeatedly hanging off of the rail.
I plan on as closely as possible repeating that demonstration and comparing the results.
This will answer a few questions.

Did the same force generate the same roll
Did the roll period change?
do the fins dampen the roll with less oscillations.

While this test is not really representative of real life, it is repeatable, and any differences will be apparant.

[joe440]

40 gallons of WestSystems ? WOW!!!

[Tony Bacon]

Beautiful job, especially the way the leading edges taper from the hull out in the front and show the 4" to 2" taper. The rounded edges also very nice.

[Simonsen]

It looks like they did a fantastic job Kevin, Whether it "works" or not, it's going to do something!

[joe440]

Commented on wrong post. Deleted.

[[email protected]]

Looks great = Perfect choice of yard.
- looking forward to sea trials!

[ksanders]

Well, I am literally watching paint dry.

Under the jack stands they have had to apply primer, three coats and then bottom paint, two coats.

Launch is tomorrow afternoon. There is a daily breeze of 10-1k knots which should give me good conditions for a sea trial.

[Tony Bacon]

you got us on the edge of our seats Captain!

[SteveK]

Yabut, no pictures of the paint drying. You tube to the rescue

https://www.youtube.com/watch?v=PLOPygVcaVE

[SteveK]

Is the paint dry yet? Is the launch before or after siesta

[ksanders]

Today was the big day.

They decided to use blocks to support the pressure of the straps against the fins.
They didn't think they were necessary but they were taking no chances.
Very professional.

[ksanders]

Then I got underway.

The first thing I did was ramp up to my normal cruise RPM of 1250 and I read 7.1 knots.
Looking back in my log book the last time I had the boat bottom painted I measured 7.3 knots at 1300 RPM, so as far as I'm concerned I'm about the same speed.

The wind was blowing at a measured 15 knots gusting to 25 using my Davis Weather Station. The seas were what you'd expect, maybe a meter or so. This is the pacific with no protection.

So, I turned beam to the wind, cruising at 1250 RPM. In these conditions I would notmally tack about 45 degrees off the wind for comfort.
Not today. The boat was extremely comfortable.

I have a inclinometer and measured mostly about 3-4 degree rolls with an occasional 6 thrown in for good measure.
I wish I had the app on my phone before, but oh well.

This is VERY subjective, and VERY preliminary but this one little trip my opinion is that the bilge keels were a huge improvement in comfort.

I need more time in the boat to get a better feeling, and I need to anchor out to determine how the boat reacts in real anchoring conditions, but so far I am super duper happy.

[SteveK]

👍👍

[PFW]

I was up in Juneau earlier this month and the boat next to my sons had rolling chocks installed. The only difference I could see was there was about a 2 foot long section of chocks removed at the lifting point of the boat not only did it identify the proper lifting point, but negated the need for blocking. I didn't think much of it at the time but now it could make some sense... By the way Kevin what a great modification and well executed...

[Jim_Gandee]

Glad you’re happy with the result!

[ksanders]

Glad you’re happy with the result!

Thanks!

Again, i need more sea time but I noticed something different in the motion.

The change to the boat is not just the magnitude of the rolling.

The velocity of the rolling was substantially decreased. The motion was more gentle in nature.

In a month I am transiting back down the baja for my winter cruising grounds. That trip will really let me experience all the different wave conditions.

[ksanders]

Here are before and after videos of my boat showing the differences in reaction to rolling force.
It's a pretty dramatic change.

first it was a lot harder to get the boat rolling.
The total number of rolls was cut almost in half
The hulls natural roll period was increased as well

https://www.youtube.com/watch?v=dpRVn3B_jb8

https://www.youtube.com/shorts/_iA0G8fG9k4

[SteveK]

seeing is believing. (poor stantion)
When are you headed out for a sea trial longer than the short test?

[ksanders]

seeing is believing. (poor stantion)
When are you headed out for a sea trial longer than the short test?

Probably not for a month when we leave for La Paz. Plenty to do between now and then.