At what point is boat considered "on plane"?

[kshelly]

This question is so basic I'm ashamed to ask, but when is a boat considered to be "up on plane"? I run a 19' bow rider with a 115 Johnson. Even at WOT the boat appears to cut through the waves without the front of the boat raising out of the water much. Bottom line...how do you determine what is "up on plane" and how much of the boats bow should be out of the water at that point???

 

[crazy charlie]

Re: At what point is boat considered "on plane"?

"ON plane" means that the boat is no longer working to get "UP" in the water.The bow does not necessarily have to be up.The bow will rise while the boat is getting on plane but will come down and the stern will ride much closer to the surface of the water than when at rest.The entire boat is moving easier on top of the water than when it is displacing the water.Charlie

 

[kshelly]

Re: At what point is boat considered "on plane"?

Ok, I guess I need to get hit in the head with a brick, because I still don't quite get it. How would you know your boat has difficulties reaching plane? How would you know everything's "normal" or not?

 

[GraphicByNature]

Re: At what point is boat considered "on plane"?

I know my boat is on plane when it glides across the water instead of working to get through it. Everything is smooth and easy, and you can back off the throttle while maintaining speed. If your boat feels like it is laboring, chances are it isn't quite making it up on plane.

 

[crazy charlie]

Re: At what point is boat considered "on plane"?

The problem you may be having understanding could be because you have too much prop on your motor and your rig goes immediately on plane.That type of prop is used if you pull water skiers.What normally happens is that you throttle up and the bow rises and the stern stays deep and you throttle up more and at a point the bow will come down and the speed will increase and you may need to throttle back a little.My rig really works to get up on plane and when it does at that moment the boat instantly goes like a bat out of hell.Race boats go nowhere with the motors screaming at first and then they plane and it looks like they got shot out of a cannon.If you still dont know what I mean at this point then you either have a big prop on your boat or you never plane off at all.Charlie

 

[gspig]

Re: At what point is boat considered "on plane"?

Here's how I know I'm on plane. As I increase speed, my bow will rise. When I hit plane the bow will drop and the boat will feel level.

 

[analog]

Re: At what point is boat considered "on plane"?

When my boat hits the plane, I feel a slight "slipping" sensation. It's a seat of your pants feeling, almost like you hit a patch of ice. and the back of your car wiggled a bit. It is very subtle, but with it comes a nice bit of acceleration, and I can back of the throttle a bit, and keep the same speed. Also, in my boat, a quick look behind tells me my wake is MUCH smaller when on plane.

 

[Ralph 123]

Re: At what point is boat considered "on plane"?

Here's how I know I'm on plane. As I increase speed, my bow will rise. When I hit plane the bow will drop and the boat will feel level.

and the boat will increase speed at the same throttle position...

 

[mjbrueck]

Re: At what point is boat considered "on plane"?

You're up "on plane" after the bow has passed the bow wave. When you're running at slower speeds, the hull creates a "bow wave" in front of the boat. When planing, the boat is riding on the flat section of the hull (the back 8 or so feet of your hull isn't curved). The V-ed bow cutting through the water creates some drag, but it's a part of the design to break oncoming waves to keep them from rattling your kidneys.

 

[Solittle]

Re: At what point is boat considered "on plane"?

The easiest way for me to tell is by the sound of the engine and rpm. You will notice a large increase in rpm when you get up on plane (as well as an increase in speed). The motor no longer has to push the water aside as the boat is riding on top of the water - "on plane".

 

[Maximerc]

Re: At what point is boat considered "on plane"?

I have heard some say when the water no longer touches the transom your boat is "on plane" ..

 

[JasonJ]

Re: At what point is boat considered "on plane"?

Just look behind the boat at different speeds. When on plane, the water will be white all the way across, and have the same shape as your hull for a few feet from the transom on back. The wake given off the hull will be moderate, depending on hull design. The hull should be running on the last 1/3rd of its surface, depending on the hull design. When the boat is trying to get on plane, the bow is high, and the back of the boat looks like it is wanting to sink. You'll see a large swell behind the motor, and the water will be green and white. Different hull designs give different results. A boat that is near flat at the transom comes on plane much easier than a boat that has a more pronounced V to the hull at transom. If you have power trim, trim all the way in, give 3/4 to full throttle. The bow will come up, then back down. Once the bow has come down, speed and rpms will climb. At this point you want to trim out. Trim is something you want to experiment with, as different speeds benefit from different trim settings. Don't be afraid to experiment. Unless you are on an 80 mph bass boat, you can't get yourself in too much trouble.

 

[Snowdrggn]

Re: At what point is boat considered "on plane"?

Here's a picture of my inflatable just as it is crossing its bow wave to break on to a plane.<br /><br /> http://img.photobucket.com/albums/v48/Snowdrggn/Zodiac/Dscf0051.jpg <br /><br />JasonJ, Is this what you mean by the wake being "white" ??? <br /><br /> http://img.photobucket.com/albums/v48/Snowdrggn/Zodiac/Dscf0060.jpg <br /><br />Cheers

 

[Wingnutt]

Re: At what point is boat considered "on plane"?

Unless you are on an 80 mph bass boat, you can't get yourself in too much trouble.<br />

LOL. I still remember that post. I don't think he ever made it back here after he got everything ironed out. It wasn't a gut-buster, but it was good for a chuckle. <br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=006841#000033

 

[BoatBuoy]

Re: At what point is boat considered "on plane"?

This all sounds kinky to me. <br />"As I increase speed, my bow will rise"<br /><br />"Everything is smooth and easy, and you can back off the throttle while maintaining speed"<br /><br />"The bow will come up, then back down. Once the bow has come down, speed and rpms will climb"<br /><br />"The bow will rise while the boat is getting on plane but will come down and the stern will ride much closer to the surface of the water than when at rest"

 

[bubbakat]

Re: At what point is boat considered "on plane"?

read this and it makes better sense.<br />When on plane you really are rolling the wave you created by pushing your boat faster thru water. You then get the boat up on step hence the boat is almost over the wave. When you reach plane it is riding with the back of the boat on top of the wave with the lower unit just under the water.<br /> http://nauticusinc.com/tech_bulletin/nauticus_pdf_book.pdf

 

[jlinder]

Re: At what point is boat considered "on plane"?

On my boat I know that it will get up on plane at about 2400 RPM. Below that level, as I slowly advance the throttle the bow goes higher, and while the boat goes faster with higher engine speed you can tell it is working to move.<br /><br />If I give the throttle a little nudge up to 2500 RPM the boat starts to get on plane. The bow starts to drop, the speed picks up more and more and the RPMs start to rise as the speed increases. I actually have to pull back on the throttle to keep it at 2500 RPM.<br /><br />You might want to try slowly advancing the throttle about 200 RPM at a time, keeping it at the new RPM level for about 5 seconds. At one point you should notice what I have described above. At that point you are on plane.

 

[cobra 3.0]

Re: At what point is boat considered "on plane"?

If your bow is plowing water, your trim setting may be way off. You should trim your boat up to just before it starts to porpoise. If this is set correctly, it will be very evident when you are going to be on plane. I'd guess that planing occurs somewhere around 20 mph on a properly trim adjusted boat of your size. Unless you are loaded with lots of extra weight/people and gear...or water logged foam?

 

[daddy_coole]

Re: At what point is boat considered "on plane"?

isnt it funny how everyone describes it differently . <br /> for me its when the missus starts to turn green and scream at me or when i hear that slapping noise coming from under the boat and the feeling that its balancing on something

 

[rnsi]

Re: At what point is boat considered "on plane"?

<br />for me its when the missus starts to turn green and scream at me <br />

I know those screams all too well.