How deep should my prop be in the water

A transom mount transducer can be angled from 3 to 16 degrees if required. I run my anti-cavitation plate a good 6 higher than yours.

If you have a short shaft motor the top most part of the transom and the lower most part of the boat should be about 15 to 16 inches.

How deep should my prop be in the water. How to set propeller depth in the water. Three inches higher than the transom is a bit high. The reason all the water is splashing in is because the lower unit is too deep.

It causes drag and the cavitation plate large fin over prop is also too deep making the set of fins above it. Prop shaft height On slower boats running the prop shaft a little deeper in the water will give you a little mechanical advantage to lift the bow up a little higher and free the boat up for more speed. Heavier boats usually need the prop a bit lower to lift the bow.

On 19-21 V bottom boats usually around 3 below the bottom is a good place to start. The depth of an outboard prop is relative to the draft of the boat. The prop has to be below the hull.

The draft of outboard boats varies - outboards are used for everything from an inflatable dinghy to a forty foot fishing boat that draws 3-4 feet. How shallow is this water. As long as the prop is fully submerged youre probably fine.

As long as the prop is fully underwater you should be good. As long as the prop Isnt disturbing the top of the water its deep enough. However they seem to like to maneuver better the deeper they are.

Then you can trim the motor up or down rotate in small increments to get the best performance from it. If you have a short shaft motor the top most part of the transom and the lower most part of the boat should be about 15 to 16 inches. For a long shaft I think 20 to 21 inches is correct.

On a 25 hull youre looking at about 3-5mm typically. For a hydro you want the bottom of the prop set to a depth so that when resting on the drive dog prop removed and the sponsons the hull is at the ride attitude that you want. You want the props as deep as possible to avoid or at least reduce them ventilating in lumpy conditions.

My propellor shafts are 400mm below the waterline. Honda 20s with the 703mm leg Your rudders will touch in deeper water than the outboard will anyway so dont worry too much about that. Get them in deep.

Lightweight boats with the prop deep in the water or a high-powered boat with a lot of lift built into the hull design often use smaller diameter propellers. A transom mount transducer should be tilted slightly forward down towards the bottom when the boat is in the water so that as the boat moves there is a smooth flow of water running across it. A transom mount transducer can be angled from 3 to 16 degrees if required.

You may wonder how deep your prop should be in the water. And the rule of thumb is that you should keep the cavitation plate level with the bottom or keel of the boat. So you should just measure the height of the boats transom from the center down to the lowest point of the hull and compare transom height with the outboard shaft length numbers.

The propeller slip is not a steady factor but is constantly changing even in a particular combination of engine-boat depending on their speed. In general the slip values decrease as the speed of the boat increases. It takes its maximum value just the time the boat goes from displacement to planning as the big wave which is created under the.

To me logically it would be WOT but some sites suggested cruising speed. Also some info I read last night suggested the cavitation plate should be 1 above the keel for every 12 from the transom so at 6 from the transom your cavitation plate would need to be about 12 above the keel and so on. In general though the top part of the trolling motor head should be about 12 inches below the surface of the water.

With that in mind you might think you can just measure from the place you plan to mount the trolling motor down to the water line then add 12 inches to determine the proper shaft length. If the Prop is significantly lower than the bottom of the boat it acts as a drag. Since it looks like you have a flat bottom boat which is what I have for my electric only boat think about how far below the flat bottom the prop is.

Basically you want all the water that the prop is pushing to glide ride under the boat. This depth will vary depending upon how wavy it is. If you set the motor too deep you run a greater risk of hitting objects fouling the prop on weeds and tearing up the prop andor bending the shaft.

I usually keep mine a little deeper than it needs to be so when the wind picks up I dont have to mess with it. Prop Twist prop rotation - This refers to clockwise right hand or counter clockwise left hand prop rotation. IO or OB prop roation creates an up-thrust of water or a down-thrust of water and has no affect on a high speed transducer when running at speed.

All water is jetted aft of the transom where your transducer is installed. If I had to guess based on my experiences with the lift and never meusring it Id say 12 inches. The place where the bunks touch the hull is well above the draft line of the bottom of the prop.

Edited June 12 2014 by Indyxc. Personally I will not take my boat into an area with shallow water that has a depth less than 24 2 feet and I use my depth alarm to let me know when I reach 4 feet so I can take appropriate action to get into deeper water. The prop on my pontoon boat is typical in that it sits approximately 4 lower than the pontoons so realistically the boat will run easily with at least.

Even though twin engines use more fuel the efficiency of the exposed propellers is greater. Notice the keel is slightly deeper than the bottom of the propeller and only the prop shaft interrupts the flow of water to the propeller blades. The rudder is directly in the path of the propeller blade and operates at high efficiency.

It really depends on conditions. In shallow water you want it up as as high as you can get it without it hitting bottom. In rough water you will want it as deep as you can go.

Anything in between the depth really doesnt matter that much. Propeller slip also known as prop slip is a critical statistic that directly affects performance. The simplest way to explain prop slip is to think of a screw.

Each time a screw makes a complete turn it has completed a pitch Pitch is the distance the screw traveled during one complete turn. A propeller turns in much the same way and also has a pitch. The problem is that water produces.

The more deep your wake boat is in the water the larger the wave will be. A propeller with a large diameter will give more transmission of power from the engine to the water. Your propeller should also have lower pitch.

Pitch is the distance traveled by a propeller in one full rotation. The lower the pitch is the higher the number of. If your current prop is 18 pitch you are lugging you motor bad.

It needs to operate between 5000-6000 RPM at full throttle. I think your motor is plenty deep in the water. I would suspect when it is trimmed all the way down it throws a lot of water out to the side when running at speed.

I run my anti-cavitation plate a good 6 higher than yours.