Method to deploy payloads

Hello everyone,

I’m a PhD student in Hawaii and soon I’ll have my hands on a Trident for research surveying the health of Hawaii’s mesophotic coral reefs (~250-300 ft in depth). I’m also hoping to use the Trident for another aspect of the project: conducting timelapse surveys of coral growth in these habitats.

I’ve already developed a specialized camera that fits into a GoPro housing and will operate continuously for a month. In my experiments these cameras are mounted above tiles (bolted to the seafloor), onto which corals settle and grow. Recovering the cameras will be fairly straightforward via a line-threading arm and carabiner clip - the problem is deploying new cameras into the exact same position to continue monitoring. Currently I’m thinking that my monitoring tiles will have a keyed, vertical PVC pipe over which another PVC pipe fits/slides onto. The camera will be mounted (facing downward) to this second PVC pipe and the two pipes keyed so that they lock into position when facing the correct orientation. Then I just need to securely carry and deploy the camera by fitting one pipe over the other.

Two questions:

  1. How quickly can I ascend and descend the Trident to 300 ft without risking water ingress? I’ll have about 20 stations to rotate cameras onto/out-of, so the faster I can return to the boat to attach new cameras the better.
  2. Any links to, or suggestions of mechanisms to carry a neutral payload and deploy it with a fair degree of accuracy? Or thoughts on the current proposed mechanism?