I have this project, an RC Boat which can be operated in shallow wateris there a way i can measure the depth of water below the RC boat? what sensor should I use?the boat will be deployed in a maximum depth of 1m.The boat should read the depth at least a foot below it up to a meter..
There are a few online stores that sell underwater ultrasonic transducers, e.g. in the UK Maplin and Rapid sell this one http://www.rapidonline.com/Electronic-Components/Underwater-ultrasonic-transducer-200KHz-plastic-case-35-1810/?source=googleps&utm_source=googleps.
No, these transducers work at 200KHz, whereas the ones in ultrasonic modules for use in air are more commonly 40KHz.
The only cheaper way I can think of is to make your own ultrasonic transducers from raw piezo elements (these are available - or at least used to be - because a long time ago I used them for tuning the frequency of lasers). You would need to machine a tapered metal block to mount them on, in order to match their stiffness to the compressibility of water. And you would need to waterproof them.Or, with help from Google, you may be able yo find some less expensive transducers designed for use underwater. Remember, it's not just that you need waterproof transducers, you also need a reasonable acoustic impedance match between the transducer and the water it is immersed in.
is the water clear or muddy?