Strakes and chines,

[jurgenscraft]

Strakes and chines,

I notice that quite a few boats have strakes going half way down the hull and the chines being reversed , my boat included, I have asked quite a few, so called,local boating experts and have yet to hear a simple answer. Why do some boats have strakes all the way to the back of the hull and how will this effect handling or should I say turning the boat,my hull has two sections where the strakes end which work like air traps and help get the boat onto the plane pretty quickly.<br />What effect has reversed chines have on handling,were on the web can I get info on hull shapes,Kind regards William Wright,

 

[umblecumbuz]

Re: Strakes and chines,

Re: Strakes and chines,

If you want expert articles on hull design, try this useful website:<br />www.boatdesign.net

 

[JasonJ]

Re: Strakes and chines,

Re: Strakes and chines,

Strakes, or lifting strakes as they are known, simply provide flat surfaces to help lift the boat up onto plane. That is their main function, with an ability to hold course in turns without sliding or tripping as a side benefit. <br /><br />Reversed chines mainly help to provide a more dry ride by knocking the spray back down towards the water. They also have the side benefit of improved handling in tight turns. The least desireble hull design would be a flat bottom hull with soft (rounded) chines. It would ride rough and handle poorly in turns.

 

[steelespike]

Re: Strakes and chines,

Re: Strakes and chines,

I have to disagree on the flat bottom with soft rounded chines.Most boats with the rounded chines that have a nice gentle run bow to stern with the flatter run aft to help it to plane.These boats handle very nicely ride smothly and with the addition of spray rails keep the spray down<br />for a dry ride.When pushed very hard into a turn they simply roll inward very pridictably<br /> and with wonderfull control.Now if you are talking a 17 footer with a 100 hp yes a full bore hard turn could cause trouble but I think any design would have to be careful.These will run as smooth or smoother than a true deep V without the tendency to run on one side of the V.<br /> I can't be sure but I think when running dead slow it will wander less too.<br />Unfortunately when you put the semi V forward with soft chine aft you lose a lot if the good<br />caracteristics.<br /> Now a jon with soft chines is not a real jon but would handle more safely but still ride pretty bad.

 

[JasonJ]

Re: Strakes and chines,

Re: Strakes and chines,

I've been on enough flat-ish boats with soft chines to know that they can be more unpredictable at their limit even with modest power than a boat with more agressive deadrise. The ride is great on flat-calm water, but you get chop that is more than a foot, and it is either displacment speed or pound-o-rama. A flat sterned hull with soft chines can only heel over so much in a turn, then you have to hope that the prop ventilates before the aft end starts to slip. Obviously it all comes down to knowing how to handle a boat within the limits of its design, something you don't see all the time...