Flare, Boat Ride + stability.

[crankit]

Hi

I own an old alloy riveted planing hull boat and I'm looking at ways to improve the ride.

Here are my gripes

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Could this flare be giving me a rougher ride?
will removing it cause a stability issue?
Reason I ask is a friend has the same boat without the flare and it seems to push through the chop better at planing speed, but it is a very hard boat to trim side to side.

Also would it be advisable to add a fuel tank at the very front of the boat? Will that soften the ride?

[charmc]

Ride in a chop is affected by many factors. Reducing speed, for example, will improve the ride quickly. Ride angle is another factor.

Fifteen degree deadrise falls, I think, into a "moderate vee" category. They're known to pound in chop at anything more than a moderate speed.

"With a relatively flat 18 degrees of hull deadrise, the two-foot seas extract a modest amount of rattling from the moderate pounding." Boating World test report of a 31' fiberglass cruiser

Lowering the bow/reducing the ride angle might help some, but a moderate vee hull simply won't go as fast as a deep vee in rough water without pounding.

Designers here are better qualified to tell you if removing the spray rails (what you call flair) will improve the ride. I think any improvement would be small and come at the expense of a very wet ride under nearly all conditions.

[kengrome]

What you've circled is not "flare", it is an external chine logs that probably also serves as a lifting strake of sorts, or maybe even a spray rail forward. If your goal is to create a smoother ride, taking it off probably won't make much difference in ride quality -- but as you've learned from your friend it will make the boat harder to handle.

Just slow down if you want a better ride, or do something else -- like get a new boat that you already know rides better. From what I hear there are lots of cheap power boats for sale these days. Maybe you can trade yours in for a better riding boat?

[Ike]

Taking off the chine logs (or lifting strakes) will also make your boat a much wetter ride. The strakes deflect spray and waves down and away from the boat, keeping the spray out of the boat and away from you.

Putting a tank up forward would be a mistake. It would completely change the planing characteristics of the boat but not necessarily improve the ride. In fact when the tank is full it may result in a wetter boat and a situation called bow steering, where the bow digs in and tends to lift the stern out of the water reducing the ability to steer. As the tank empties all this would shift backto the stern again. Better to keep the tank aft.

[Pericles]

The deadrise is given as 15 degrees, which is probably at the transom. Deep "V" boats with a transom deadrise of 22 degrees can have a smoother ride through waves at the expense of economy whilst running and rocking when at rest. Everything is a compromise. Brian Eiland posted an article "The need for speed" from his website, which although was written in 1993, charts the development of specialised fishing vessels that mirror some of your experiences.

http://www.runningtideyachts.com/arc...dforspeed.html

Don't remove the flat chines. They promote earlier planing and give some stability at rest. In your case they probably hold the hull together. Have a look through here.

http://www.bruceroberts.com/public/H...escription.htm


Pericles