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Quick and Dirty Deadrise Angle Measurement Method


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I was just told that there are aps for smartphones that have angle measuring capabilities,... 

Not knowing this yesterday, I came up with a quick and dirty method to measure a hull's deadrise angle using the EDIT function on an iPhone.

This method requires the boat be on level ground (jack stands etc.) and a wall or a piece of straight lumber be positioned perpendicular to the keel of the boat.

Hold the iPhone against the hull with the long, flat, "top" side of the phone parallel to the hull.

With the phone in contact w/the hull as above, take a picture looking at the wall or piece of lumber.

Go into the EDIT function for the picture and select CROP.

Use the ROTATE function to make the piece of lumber or base of the wall parallel to the gridlines in the edit function display.

Read the angle from the display near the slider you used to make the grid parallel with the wall.

The further away the wall/lumber is and the longer the wall lumber is will help improve the accuracy.

I actually believe this is good enough to work within the accuracy required to order a tilted sonar transducer. 

 

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HB2.

Yup, that'd work!

I had a level w/me, but not a speed square. 

I also have a angle indicating level, but not w/me, either. 

Just trying to share the quick and dirty method. Most everyone has a cell phone nowadays,..

'Best,

Neil 

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I was just told that there are aps for smartphones that have angle measuring capabilities,...  Not knowing this yesterday, I came up with a quick and dirty method to measure a hull's deadrise angle using the EDIT function on an iPhone. This method requires the boat be on level ground (jack stands etc.) and a wall or a piece of straight lumber be positioned perpendicular to the keel of the boat.

Hold the iPhone against the hull with the long, flat, "top" side of the phone parallel to the hull.

With the phone in contact w/the hull as above, take a picture looking at the wall or piece of lumber.

Go into the EDIT function for the picture and select CROP.

Use the ROTATE function to make the piece of lumber or base of the wall parallel to the gridlines in the edit function display.

Read the angle from the display near the slider you used to make the grid parallel with the wall.

The further away the wall/lumber is and the longer the wall lumber is will help improve the accuracy.

I actually believe this is good enough to work within the accuracy required to order a tilted sonar transducer. 

 

 

 

If you check both sides with a cell phone and determine the average of the two readings, the boat doesn’t have to be level (nor does the line you check against) so there’s no need to jack a boat and check it with a level. 

You can also hold a straight edge along one side so it extends past the keel and measure the angle and divide by two, and/or rotate the image so the straight edge and hull match the horizontal grid. This method also doesn’t require the boat to be level.

 

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John,

Brilliant! Why didn't I think of that? You don't have to answer,...

Guess I was just lucky that the boat was already jacked up and sitting level and square against the wall ;-)

For a pretty stupid post topic to begin with, this is really working out for me!

Thanks!

Neil 

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