I’m looking for some help with a little project. I want to measure water depth. But, I want to measure it with the sensor being inside the boat. The sensor can’t be placed on the outside as it will simply be torn off by the moving water.
I found this video on YouTube which is great but it only operates in the water. Drilling a hole for the sensor is not an option.
This is what I want to achieve:
I assume that means that the boat will be moving - possibly at some speed - whilst the measurement is taking place?
I know little of depth sensors but I'm pretty sure that they would need a unrestricted "view" of the river/sea bed in order to perform the measurement. But initially, it seems you require a sensor that can "see through" a steel / aluminium / fiberglass hull?
EDIT: A quick search and I found this sensor:
Hi Mark,
Yes the boat will be moving at speed. And it will need to see through Carbon Fibre and wood but only around 1cm.
I also want to display the depth reading on a small screen attached to the arduino.
Ok. I found some more details on that sensor I mentioned earlier:
Says it is suitable for fiberglass hulls - not sure how that would translate to a carbon fibre hull.
Would that work with an arduino?
The sensor is quite expensive.
I was hoping to maybe calibrate the sensor in the YouTube video to ignore the first 1cm then take the reading. Or would the hull completely bock any signal from it?
It doesn’t have to measure a massive depth. I just want to measure the water depth so I know if we’re going to hit the bottom.
Basically an early warning system that can tell me when the water is getting shallow
If the sensor uses ultrasonic technology, then the hull would very likely block the signal.
Is there an area on the stern of the boat externally you could attach the sensor to that wouldn't be in the direct flow of the water?
No there’s no way I can attach it outside of the boat.
This is my main issue. I need the sensor to be inside the boat
Too inelegant just to hang it over the side?
It’s not an option.
The main reason I posted on here is because the issue I have is the sensor has to be inside.
Ultimately, I want to build a small box with the sensor and a small screen that can be attached to the inside of the hull.
Your only option is to try commercial sensors designed for that purpose and decide if they work well enough to be useful.
Measuring water depth through other materials It is a very difficult technical challenge, so expect to spend a significant amount of money for something that actually works. This is not an Arduino project.
The sensor can’t be placed on the outside as it will simply be torn off by the moving water.
Certainly not by water, but maybe, if you hit something. Installing flush mount transducers
Some thoughts on your project:
Look at the offerings from boat electronics companies. Sailors would love to avoid having a through hull to enable the depth meter, but a brief google shows me that the major players don't have such a thing.
I'll guess that it's too hard to configure such a thing for different hull thicknesses and materials. Maybe you can get one working as a one-off for your boat.
The big sail boat I owned had a depth sensor inside the hull in a water well.
It measured through the fibreglass hull.
Leo..
You could try the relatively inexpensive DS1603L.
It may work if you remove the wood so there is just one layer of carbon fiber to "see" through.
There is an Arduino library for it.
Would need to be in tight contact with the carbon fiber and have a viscous coupling fluid between it and the carbon fiber. Try silicon grease.
Get two sticks, each one meter longer than your draft and mark twain... if you really work boats.
