Quote: I do carry a sextant and tables as well, which is a bit over the top for the channel...)
Over the top? Are you kidding? It's totally inadequate. It's far more vulnerable to breakage than a £60 waterproof GPS from Millets and half the time it's cloudy and there's nothing to get a fix on at all.
The biggest joke is that you seem to be claiming your sextant is not electronic yet since quartz watches you will almost certainly be relying on an electronic watch to tell the time. Unless you are going to claim that a clockwork watch is more reliable?