[usrusr]

The good news is that we do have a bit of experience with metal machines that operate in sea water for decades. We (as in humanity, I don't) know exactly what to expect. You'd want to have a permanent service operation scaled exactly to how much overhauling capacity you need to put the tide kites in a round robin maintenance loop.

[hoseja]

And yet, every other tidal powerplant has been rendered hopelessly useless by barnacles.

[usrusr]

Have they? And how many of them can be ordered to surface under tide power, for easy maintenance access and towing into a maintenance dock without involving expensive divers?

I presume the tether on this would be built long enough for controlled surfacing, a longer tether means larger deadzone between inbound and outbound tide, but there won't be much energy in the flow close to the turning point anyways.

[Sammi]

We are perfectly capable of removing barnacles from ship hulls. What makes these kite hulls different?

These are just fancy boats you know.