Looking for input about this video of surface drives
 

https://www.youtube.com/watch?v=0AjoyE13YMI

apparently its a 42 fountain and unless I'm blind the hull never touches the water even at an apparent 50 mph, can someone explain to me what I am looking at? apparently hull design no longer matters? or is it just a notch?

yes the camera is up in the notch on the transom, which puts it probably five or six inches out of the water any time its on plane. I like the telemetry and one know what kind that is?

As Dave said and as you can see in these pics, the notch is just that, a notch. In that video the notch is out of the water when on plane but the pad is still very much in the water.

Its a Garmin Virb.

https://virb.garmin.com/en-US

Is it typical for a surface drive to ride so high at such a low speed? With all the talk about speedmasters only being effective over 80mph I assumed thats was their approximate planing speed

It is not the gear case the determines the planing speed. It is the hull. Speedmasters are the preferred gearcase over 80 MPH due to them being able to be surfaced as in the video. That is when the "magic" happens!

A true surface drive is designed to be about 50% out of the water when the boat is on plane. My Kaama drives as soon as the boat crawls up on top of the water and level out the drives are running half submerged at 0% trim. I can of course trim them up and down and change the depth! Unlike a stern drive positive trim doesn't do much with a surface drive because you are basically pulling the prop out of the water!

I shot this video this summer. You can't see a whole lot but you can see the blades spinning and you can kinda see they are only half submerged!

https://youtu.be/X2JYRgf1uRc

http://www.offshoreonly.com/forums/a...91758_n-1-.jpg

Damn that's sexy!!!

probably one of the best surface drive videos https://www.youtube.com/watch?v=Of1RY4M8VqM

Marginnm, thats a very nice ride!

Thank you - for leaving me an opening to post some more surface drive porn :evilb:

Did you notice any difference in the driving and planning ability of the boat with the prop guards on ?

None at all.

That was nice to hear , I want to get a set but was told they might affect it's ability to get on plane

So why does it have stacks. I thought they were to air the blades.

almost as good as the real thing Marginmn!

That pic shows that the camera would be mounted between the running pad and the drive above the pad. Picture really clarified where the camera was mounted.

https://www.youtube.com/watch?v=6YkFUnegjIY

At the 2:30 mark is a slow motion of the wetted running surface of a cat.

Marginmn what props are you spinning? I have the kits on my Gun. Spinning 18.25x30x18 herings now but power up grade is in the works.

Ben Robertson has been around a ton of Fountains, and it appears that the drive height for those #8 drives is perfect, that is why it cost $$$,$$$.00 to have the right people rig the right boat. How fast is a new 42' with 1350's and #8 drives? at what rpm, gear ratio, prop size, ect...

I currently have a set of 18 x 33 16's on her but could use a little more pitch.

Just to be clear the Ben Robertson video shows either Speedmaster number 6 or M8 drives, not surface drives. The camera is mounted in the notch of the transom. At high speeds the goal is to obtain 40% propeller engagement in the water and 60% out of the water surfacing, essentially the lower section of the propshaft bullet should be on the surface of the water. This video shows perfect X-dimension drive height in my opinion, for a high speed application.

What are you Arneson guys seeing for slip and what was the worst slip % you've seen??

I am not running arneson but instead kaama's. I am averaging about 16-17% with my 3 blade props. The worst slip I saw was about 50% when I was still learning to drive with the kaama's and that's because I had them pulled 3/4 of the way out of the water! :( live and learn!

One of the best!

when a stern drive is that high and spinning the same prop is there really much difference?

Double post