I've only done land based fiber design, but I would assume based on my experience in that field that one of two things happens. First option, there's some slac

I've only done land based fiber design, but I would assume based on my experience in that field that one of two things happens. First option, there's some slack somewhere nearby to do a pull nearby. If you ever pay attention to aerial poles, you'll see at various intervals things that are vaguely reminiscent of a snowshoe or tennis racket, in the industry they are in fact informally referred to as a 'snowshoe' and the entire purpose is to have some fiber to 'release' if a cut happens and a resplice is needed. [0] I'd -assume- there is an analogue for these in undersea cables... If not, well then you'd have to splice a length in and probably have the right sort of mechanism to ensure the cladding/etc stays contiguous (maybe even weld? IDK) but regardless you're probably talking... Actually wait yeah they've got this all figured out; https://www.youtube.com/watch?v=QiwidMEv8CM https://www.youtube.com/watch?v=QiwidMEv8CM [0] - Real world example, for instance if someone uses a fiber splice can for target practice.