(Affordable) Clamp for 6" enclosure

Hi everyone- I am using a 6" enclosure on an autonomous surface vehicle. The vehicle is a small catamaran. The enclosure needs to sit vertically in the frame in between the pontoons. I want to hold it there using a clamp like the one in the picture

The picture is for an ADCP and that product is way out of my price range. Does anyone here know of something similar, either available for purchase in the ~$100 range or DIY?

Thanks!

Bumping this old thread — it’s been a few years since Daniel’s post, but there is no first-party clamp in the store.

Blue Robotics publishes a 3D printable enclosure clamp design for 3" and 4" enclosures. It probably wouldn’t be too hard to make these parametric?

What solutions have people found?

(The photo above is of a DeepWater Buoyancy Universal ADCP Clamp, for the curious.)