You're totally right, I linked the wrong paper. This is the right one https://link.springer.com/content/pdf/10.1007/s13320-013-0140-5.pdf
As you can see they incorporated optic fibres in the hull of an America's cup class vessel. Again the approach described is heavily based on interference (Brillouin scattering).
The idea is to have a "Mayday" signal being transmitted via Xbee in case a hull breach is detected. I already have leak probes inside the boat, but for instance they can't detect if the bulb detaches from the main hull or the keel gets damaged.