Spray Knockers

rossjo · Post by **rossjo** » Thu Jan 27, 2011 11:22 am

Maybe you should rename your boat "Nice Knockers" ...

Paul · Post by **Paul** » Thu Jan 27, 2011 11:23 am

Vic · Post by **Vic** » Thu Jan 27, 2011 11:33 am

Not going to change the name. But, I will be knocking soon.
Just ordered a kit from Smart Rails.
To be continued!

RWS · Post by **RWS** » Thu Jan 27, 2011 12:51 pm

Vic,

When the International series was first introduced with the 10 meter, much was written in the press regarding smooth, dry ride.

Those chines that run the length of the boat have a downturn on the outside.

If you ever have a chance to be a passenger on your 10 meter, take a look at the water spray that is pushed down and away from the hull while underway.

The only time we see any spray is when there is a substantial wind, driving the spray.

That said, if you are running at just above planing speed, the boat is lower in the water than when running at say 18-22 kts.

One of the biggest differences we noticed with the diesels is the tremendous increase in lift, she really gets her a$$ up and out of the water.

The wet ride thing was never an issue for us when we were running the 454's either.

Is it possible you are not getting the lift she was designed for?

Before spending $ on the spray knockers, could you post your speed & RPM numbers for us to all look at?

Is it possible that this could be more of a prop issue than anything?

The mid cabin models do differ from th eexpress cruiser models (mine) as your engine is farther aft, your shafts are shorter, the shaft angle is closer to the hull and your gear spins smaller diameter props at a higher RPM than onthe express cruiser.

Maybe some other 10 meter owners could chime in here and help out?

Am I missing something else perhaps?

It seems there should be a reason for the wet ride.

RWS

Vic · Post by **Vic** » Thu Jan 27, 2011 1:10 pm

Maybe you are right. Perhaps I am just not getting enough out of her to really step out.
The problem typically occurs, when I am running into a quartering sea with about 10 knots or greater of wind and 4/5' chop. I normally cruise at 2,850 R's, which equates to +14 MPH and most importantly to about 29 GPH of fuel consumption.
The spray is really intense on the windshield and on the bimini, when these conditions occur. Yes, some water gets into the cockpit too. But, I am not as concerned about this, as I am re the water thrown up at the bow.
Running into a head sea normally does not create much spray, unless the winds are getting close to 20.
The props are 15.5" x 16". They were blue-printed at my last haul.
I use my boat primarily for fishing. So, I have a goodly amount of gear on board. But, I am conscious of the weight penalty; and try to keep her as light as possible.
So, what do you think?

rossjo · Post by **rossjo** » Thu Jan 27, 2011 1:36 pm

Vic,

Got any pix of your boat on plane?

Vic · Post by **Vic** » Thu Jan 27, 2011 1:39 pm

Naw.
Wish that I did. She is a fine looking sight, I am sure.

rbcool · Post by **rbcool** » Thu Jan 27, 2011 1:54 pm

Welcome to the forum Vic.....looks like your on your way!!

Ron

Vic · Post by **Vic** » Thu Jan 27, 2011 2:01 pm

Liking it!

RWS · Post by **RWS** » Thu Jan 27, 2011 2:49 pm

Vic,

On my express cruiser with the 454's my best economic speed under ideal conditions was 2800 RPM 17.3 mph (15 kts) with flowscans showing (.81NMPG) which is pretty close to 1 statute mile per gallon.

I did notice that with both fridges full, plus ice chests, the freezer on the aft deck, 8 guys, beer, watyermelon and gear shw did in fact ride a44 heavy, at would be expected.

Before buying the spray knockers I would do some additional armchair research.

You may find that by improving effeciencies and performance that you ccan take advantage of those longitidunal reverse chines and by virtue of an improved running angle eliminate the spray problem.

Let's see if you can get the mid cabin guys to chime in here because while our hulls are essentially the same on the outside, there is a difference in the running gear.

What us your RPM at WOT ?

Can you confirm that the tabs are actually working?

Might be a good idea to get one of those $10.00 inclinometers like a sailboat uses (I have one on my boat) mounted fwd/aft that will show your exact running angle.

On plane is one thing.

If your boat is not getting up and out of the water as it was designed, it could be missing it's "sweet spot" being less efficient to operate, costing you fuel and pushing more water arouind, some of which is making you wet and uncomfortable.

It ias my own personal opinion that this hull design does in no way require the addition of spray chines. Just my opinion.

RWS

Hope we can help you.

Vic · Post by **Vic** » Thu Jan 27, 2011 5:05 pm

Really beginning to wonder, if there is some other problem, besides that fact that I have a mid cabin w/more severe prop angles. Your big block performance was 15% better, than I am experiencing.
What do you think about my prop size and pitch?
I rarely take it up to WOP. But, I am pretty sure that the Crusaders will wind to 4,100. I usually back off at +3,500, as the FloScans are pegged at that point!
I understand the theory, behind the Delta Conic design - not sure, why more boats did not have this bottom. I remember when Trojan and Larsen first started selling boats with this feature.
Love the way that my boat performs in a head sea - very soft; and the down-sea tracking is a pleasure - set the auto pilot and forget it.
I checked my tabs the last time that I hauled and actually tuned them up a little.
This spray deal has been a situation for all ten years that I have owned the boat. Just never thought about doing anything about it soon enough to rectify the situation at haul-out. Again, on 2/11 my boat will go on the ways.

prowlersfish · Post by **prowlersfish** » Thu Jan 27, 2011 5:54 pm

Under the conditions your getting spray , it would be hard to find a boat that stays dri , I get wet on my flybrige under similar conditions ,and its a totally different boat .

alexander38 · Post by **alexander38** » Thu Jan 27, 2011 6:28 pm

if I hit a 4 or 5 footer spray is going over the top for sure ! And hit one at 14 to 16 knots I'm putting water on the poop deck.

and my hull as good size chimes with a down turn.

rossjo · Post by **rossjo** » Thu Jan 27, 2011 7:51 pm

Vic wrote:- set the auto pilot and forget it.
I checked my tabs the last time that I hauled and actually tuned them up a little.

Auto-pilot with fixed trim tabs?

Think we found your problem.

Vic · Post by **Vic** » Thu Jan 27, 2011 8:08 pm

No, I have Bennet adjustable tabs.
I have tried them in every position from fully deployed to completely turned off and the spray problem persists.
There really does not seem to be any difference in the amount of spray, with the AP on or off. Although, I tend to leave it on a lot, when I am heading home from the fishing grounds, when the wind has typically picked up and caused the chop and subsequent spray.