When you really need to spy on whales

DiveTimor had a problem, they had a hydrophone, so they could listen and record whales, awesome, but they also wanted to know where they were. Whales can be rather large, but so is the Timor sea.

Also there was another problem ... the hydrophone wasn't working. Turned out the coaxial cable had started rusting from the jack end ... got that fixed.

There are already plans on line to build/convert a regular hydrophone into a directional one. They (apparently) work, but left the hydrophone permanently fixed into the housing. They also weren't actually parabolic. The dish around the hydrophone merely functions as an acoustic baffle, reducing sounds from the sides and rear.

So we have 3D parametric CAD, let's design an actual parabolic dish, where the position of the mic can be adjusted to the focal point of the parabola. And the microphone mount can be swapped out and replaced with a different mount and a different hydrophone if needed.

There was also the need to be able to collapse the whole thing down to a smaller size for transport, and have everything angled a little bit to make it easier to use away from the hull.

• One screw in TPU (flexible) microphone housing.
• A little custom fit plastic washer to firmly hold the hydrophone in it.
• A parabolic dish with a matching thread for the microphone housing.
• A yoga mat that did a "half lord of the fishes" to make a acoustic backing for the dish.
• A specially angled mount to connect the dish to the telescopic arm.
• A set of interlocking rings to make up the telescoping arm.
• And correspondingly angled handle to pass the hydrophone's cable through and make it easy to, well, handle.

The result is a telescoping parabolic hydrophone housing. That can be adjusted to the correct focal length for the hydrophone in use, and collapsed down to a slightly smaller size for transport.

And yes, it does work, not only have whales been recorded with it, but where they are performing their gig as well. Check it out from Dive Timor Lorosae's Facebook page.