Hi Kev, I work on ferries between Dover and Calais. Look out for money off adverts in MCN, to get the best deals. The safest way to go for your bike is the tunnel as they clamp the bike down. When you end up in a ferry, always make sure you leave the bike in gear if on the side stand. If the machine is secured to the deck over the seat that the stand (centre or side) is ahead (forward) of the lashing. As it will hold the bike on its stand.
Good luck
Twist n go