Fixing a wet ride

I have a 19' x 95" v bottom boat that tends to be very wet if I am quartering into the waves. the sides are 90 degree to the waterline.

I would like to try to reduce the spray back into the boat by adding a piece of 3" angled aluminum to the outside edge of the bottom to redirect the spray down and not out. Do you think this will work or would I just be tossing money away?

very basic drawing of what I am talking about (red lines) scale is way off.


Here are a couple of picts of the actual boat so you can see what the actual shape is:


and on the water

 

The angle is too much. The bottom of the spray rail should be no more than 4 degrees from the horizontal.

 

If you added the angle as you've drawn it, it will change the way the boat corners and trims. It will grab hard in turns and change the trim.

 

The boat has a shallow vee with what looks like a very full bow shape, but it is a little hard to say from the picture. I certainly wouldn't be adding anything to chine aft of amidships, so handling in turns shouldn't be affected. I have seen aluminium boats with similar lines employ an extrusion with some down angle on the forward curved section of the chines, but not to any great effect as the spray just explodes upward and more forward than sideways from full bow sections. You could try giving the motor some more out-trim, but I suppose the ride will suffer then.

 

I think this is what you are saying: When quartering into waves, there is usually a wind blowing from the same direction as the waves and spray thrown out by the hull gets blown aboard by this wind. As long as this spray is present, some will be blown back. At high speed, it is not usually a problem since the boat has moved on by the time it reaches the deck line. Spray rails or "wave collectors" as they were called when tried in the early 20th century have been used with varying success. They can result in higher speed as well as spray reduction but depend on the overall hull design and weight plus other factors. If you look around, you will see them on some boats such as the C Dories. Like many such devices, the proof is in the doing and blanket opinions here are not worth much. There will be some effect on handling as Gonzo says although there is no reason to have them aft as Mr Efficiency says since spray generated there will not likely come aboard.

Many boats that run in the Yukon River race in Alaska have such vertical rails in the forward part of the chine. Other designers "introduce" the idea from time to time and think it is new. My guess is that it has some value when tailored to the specific boat but I may have told you more than I know.

 

I know absolutely nothing. But normally people sitting at the rear of a boat get more spray than those at the front.

I noticed your steering wheel is at the rear, almost in easy reach of using the handle on your outboard.

Could you move your steering consul forward and avoid the spray?

 

If you put those sprail rails on the hull sides, instead of placing them at the bottom, they will imho be more effective at preventing water from rising up the sides.
Cheers

 

Moving the consol forward is not an option without a good deal of metal work as there is a bench running the full length of the side.

From what I have gathered, I really need to video the boat to see where the spray is coming from. It is more than just a light spray, it is more like getting hit with a couple of buckets of water. Not real fun when it is 20 degrees outside.

Even with the HO115 on the back, the design of the hull and the weight limit the effect of the trim.

I will have it on the water soon so I hope I can get some video and then figure out how to fix the issue, if it can be fixed.

 

Sound like bad design to start off with !!
The chines need to be turned down As gonzo said at least 3 to 4 degress to deflect the water coming out the side down onto the surface all the way from the bow to the stern . No more turn down is not better so dont thing about it !!!
Shifting the console forward is a dumb idea as its pushing the nose down even further and making the boat even wetter !!
If anything move weight aft to help Raise the nose of the hull and make the spray come out further back so theres less spray for the wind to catch and toss it upat you .
Have you played with the trim on the outboard ?? :idea:
Trim it up and shift some weight into the back ! that should immediatly make a differance before doing anything else :?:. The faster you go the better it should be .

 

Tunnels; I disagree that shifting the drivers station forward is a dumb idea. The idea is to get out of the spray zone. What with twenty degree weather, hypothermia and all. He has enough power to trim the nose as desired. The idea is dumb only because it fails to fix the underlying problem and spray would continue to come aboard aft, but not all over the helmsman.

Spray deflectors, sometimes called whiskers, appears to be the only mod worth trying. I wonder whether this boat is overloaded, as in weight/bottom area...........

 

shirting the console is a dumb idea !!!having to rewire the boat and shift everthing is DUMB !!AND IF IT DOSENT WORK THEN WHAT !!!!!

 

so are you saying that if I did what the original drawing had but at a 4degree angle down it would fix the issue?

More like this:


I have played with the trim but have not had much luck. Moving weight back does help but it does not fix the problem.

 

The lower drawing is almost right but it needs to go from the front to the back . Not just part way . Remember the angle 3 to 4 degrees downwards all the way !!!
Needs to deflect the spray down back onto the water surface so the wind dosent get under it to lift it up and over onto the boat !!
Plus if you make it reasonably wide down aft you could gain lift and the boat could go faster as well

 

Thank you Tunnels for your input to my suggestion. However doing dumb things is what I'm good at.

Rewiring a boat? I suppose, as I am in machine automation I didn't think that wiring up a boat would be difficult, although you may find it hard.

I have just moved the steering location forward on my boat. This is because I feel that when it was built, the owner was tall and couldn't fit in the cabin and put the wheel and controls behind the cabin. That was alright for him but I couldn't see over the top of the cabin and I moved it inside.

Planing boats that I have owned or seen are at too great an angle having too much weight at the stern. This is so, when they get up on the plane, they level out. However unless you want to run your boat flat out where ever you go your boat's always tipped up.

I would assume looking at your boat that it is designed to take a lot of passengers, actually looks ex army. If you are not carrying enough weight up front it could alter the way the spray comes in the boat.

May be you should try trimming the boat by putting some weight up front before you make any drastic alterations, to see how she goes.

But remember I know nothing and I only have dumb ideas, so be carefull taking any of my suggestions.

 

The other route that might help is some kind of perspex screen or the like. Failing that wear a raincoat and wrap a towel round your head like Lawrence of Arabia.