Reliability is the key
Using a non-contact link is much more reliable than a jack plug connection, which eventually starts to short out as it is affected by moisture or water. The issue is not that the item is always in water, but is in a wet environment when connecting/disconnecting sections. Of course, we already have the connectors inside steel housings with o-rings to provide a pressure tight seal, but this is not helpful when not connected. The data transmission rate is low - 20kbaud currently. I have looked for induction systems on the web, but found only one company, and their coils are very large - we really need to find a replacement link to fit in the same area (about 10mm diameter).