Need an Ultrasound sensor

Want to find a sensor that can detect an object under water, animal weighing 60kg.
The target object is a mammal with a velocity of 1-6m / sec. The size of the object is at least 150cm x 30cm.
A device or sensor that is low-power is suitable for battery use. The device is used at a depth of about 5m.


Sensors of this type suitable for underwater use are not an item currently carried by Digi-Key, either as raw sensors or as ready-to-use sensor systems.

Many commercially-available “fish finder” devices incorporate an alarm feature to indicate when an object of some general size passes within their sensor’s field of view. Perhaps a product of this type would serve your needs, or could be adapted to do so.