Around the Roostertail...
 

I've always thought the real action is back in the back and most of you know I process my shots mostly relative to the rooster. :cartman:

Looking closely at exposure and textures over thousands of images, my interest is drawn to the interaction of the hull with the water.
This really began from some direct overhead shots that show a vibration eminating out and forward of the hull (more on this later).

What I noticed on this shot of Mr Roth and Mr Tomlinson at work is the area at the base of the rooster...
the texture of the wawa totally smooths out due to the quick passing suction from the props.
One of those things you don't notice as it is happening.

http://farm9.staticflickr.com/8117/8...018dff42_h.jpg

Since so many of us spend a lot of time on and around water... what have you noticed?

I can't say I've ever noticed this before, I'll have to start looking for it going forward.

Nice picture, as always Jay!

I would think the less prop slip there is the smoother that will be...never noticed that either...you can see the "bite gap" (if that's a term LOL) in the rooster too. noticed that more in videos that pics.

Bite gap sounds good to me. I love it when you can pick it up in a shot.
When you think about the rpm that thing is turning, usually means the boat is haulin azz.

eta: the shot is from the DS Shootout, so they were sorta hooked up and dialed in.

We have noticed a few things especially with changing props and taking videos. We wen noticed a different sound with prop change. Especially when you get some air! I'll have to try and transfer my videos and post them in vid section. I need to get cracking.

That is actually a low pressure area because of the wind, not the props, making that effect - no different than the back of a SUV in a rain storm - you will see the same thing, its just pronounced here because of the speed he is running.

if that's 6's which I'm pretty sure it is. that's a surfacing lower so I'm having a problem grasping the low pressure aspect you are referring to. would be a hell of a low pressure area to settle the water down that quickly... may be my simple mind tho...will need more pictures and less words LOL.

I think the air could have something to do with it...

Water suction can be a helluva force... where is alla that roost coming from?
I remember standing in knee deep water one day, boat was beached
Fairly narrow part of the icw and a tug comes by pushing a barge...
Holy crap- he was at least 80 yds away and the current almost took me down.

I bet it is the compressed air escaping from the tunnel

I think that is what Al Gore was referring to when he was explaining "Cabon Foot Print". That's what I'll name my next boat:evilb:

For you, maybe STINKBOMB would be appropriate... :lolhit:

Glad u mentioned that, it's one of the most compelling aspects of action photography.
Stop time and take a closer look.

Will try to find a shot of another thing that looks like vibration ripples eminating from the hull due to big block vibes...

Fair enough but that's Mr. STINKBOMB with a significant "Carbon Wake Effect" to you Mr. Camera Guy!

I want to get a copy of that photo you made of my 338 in KW for the man cave. I also have another project for you. I'll talk to you later I have to go treat the world for titanium deficiency today!

You only really see that on the cats...we get it on the small boats too. It's the packed air under the tunnel creating the bit of turbulence on the water. Here's a "small" boat example just from the front side.

http://i215.photobucket.com/albums/c...ps8fea98d0.jpg

Jay.....some old school lore from the back of the boat........

If you look closely at the famous photo of Aronow in his 32 foot Cary...The Cigarette, you will notice the surrounding water is rough, but his trim tabs are up.

When I was still wet behind the ears, he told me a good way to win races is to be willing to take a beating for an advantage every now and then during the race. Even rough water races will have flat spots for a short distance. He told me when you get to them after running hard in the rough, everyone will relax and take it easy after just taking a beating. That is the time to trim up and run hard....BUT... know the flat spot will end and you will go flying again when you hit big water again.

Second point was told to me by Don's riding mechanic....Knocky House. He said it was nice that everyone was adding a type of measuring cable to the drives so you could gauge how high or low the drives were. In case it ever broke, know that you should never trim up so high the rooster tail is higher than the top of your transom. Anything higher is waste of power and prop slippage.

Remember this was back in the late 60's and early 70's long before the props available could produce the rooster tails we see now.

Hope to see you at the show. Keep up the great work, outstanding as always.

In my limited experience in big cats (true tunnels) once the roost lays down THEN your hauling ass. If there is a pronounced roost the cat is just crusin. as far as high and low pressure..........I'm out. My .02 cents. Carry on.

I've noticed that at well- very obvious in many of the sequences from a helo.
The pix aren't as dramatic, tho- so I usually don't post them.
:lolhit:

Love it when the light is right in late afternoon.

https://farm3.staticflickr.com/2935/...c04c9626_o.jpg

And this one of Chris just starting to lay down as he gets into it.

https://farm4.staticflickr.com/3730/...a56ac3f3_o.jpg

Thinking about it... where it really is obvious is when tracking someone from a helo during a shootout run.
This shot of Silver Lining is about halfway down the course.

https://farm8.staticflickr.com/7370/...029c96b1_o.jpg

It's fun to watch the big cats at the LOTO Shootout do this. One hell of a rooster at start but when that sucker lays down it's like a slingshot propelling the boat down the course. I'm sure it takes a hell of a lot of power to throw all that water up in the air. When the rooster lays down it all turns into forward propulsion. Very exciting to see!

That's great!!!!!

I'm against renaming a boat or the one I bought off a friend recently would've been either Sail Bad the Sinner or Global Warmer. :D

I believe when the boats are going slower the props are deeper in the water and water is going over the top half of the prop. The prop slings the water in the air off the top, big roost. When the boats are going fast the hull rides higher so the props ride higher. The water level is actually below the height of the propshaft, so only the bottom of the props are in the water, small roost.

Low speed = bigg slip = bigg roostertail.
High speed = low slip = small roostertail.
Better efficiency = small roostertail.