As many have said, once you introduce sea water and its accompanying corrosion, along with biofouling, “relatively simple” things become a lot more challenging.

As many have said, once you introduce sea water and its accompanying corrosion, along with biofouling, “relatively simple” things become a lot more challenging. Not to say there haven’t been massively successful drifter studies conducted by oceanographers, though the per unit cost is well more than $200. One of the largest fleets is the Argo[1] float system, with nearly 4000 floats in operation in the world ocean. [1]: https://en.m.wikipedia.org/wiki/Argo_(oceanography) https://en.m.wikipedia.org/wiki/Argo_(oceanography)