Hi penguin233,
I very much hope I am wrong about this, but I have a feeling Sport 24 (the sports channel at sea) may not have the broadcast rights for the FA Cup. They have the rights to the Premier League & UEFA competitions, but not so sure if they show the FA Cup. I don't think I have been on a sailing when the FA Cup has been on so can't say this with any certainty, but it's not listed as an event that they show on their website.
Maybe it will still be shown as it's a showpiece game, but just thought it was worth suggesting the possibility it might not be on.