Find Your Cruise
I am not going to say that your plan is impossible but it would take a great deal of organising and luck as ships visiting Egypt do not normally originate from the UK but start their cruising from a Mediterranean port. Secondly Nile cruising is normally done in the historically interesting areas of Luxor and Aswan the former being 500 miles from the coast or 400 miles from Cairo, Aswan is even further. So to find a ship going to the Red Sea would be best with a transfer to Luxor from there then you would need to be able to get a cruise ship back from the same place or Port Said or Alexandria at the end of your cruise. The best way to do this would be to take the first leg(s) of a world cruise in January and the last leg(s) of a world cruise to return. Exhausting to manage but as I said not impossible. I would attempt it. ....Neil.