Some probes that I am familiar with (at least schematically) use a weighted, bullet-shaped head to sink the probe through the water column, taking salinity and temp measurements on the way down. When a certain depth is reached, a data package is released and floats to the surface for collection, while the rest continues to the bottom. not sure of the physical size of the apparatus. recovery is not easy in high seas, so I definitely see the advantage to being able to reel a probe back in.
I was thinking along the same lines, Ann. I would also like to know more about the actual data collection aspect - types of probes, how the sensing mechanisms work and what parameters are able to be measured, as well as how the data is collected and stored...this looks like a very interesting system!
I'm curious about the relative size, weight, cost and other metrics and characteristics of the probes currently in use, to give some context for the discussion of the deployment system. For example, what size and weight are now used in current probes, vs the lighter weight and more compact size aimed at here? Also, how would the probe be designed or constructed differently so it is reusable instead of disposable?