Ferries are a nightmare for strapping down the bike safely, for one thing you have to use what they supply, and on most ferries that I use that is a 50mm ratchet strap with a big pad threaded onto it for the seat, and secured into the deck at the truck fixing crosses, the trick here is to use the side stand, as that keeps both wheels firmly on the deck, and then be sure that the ratchet mechanism in on the same side as the side stand, I try to have the front wheel against something solid, but that is rarely possible, the ferry companies do not take responsibilty for the fixing, the rider has to do it themselves, so why are they allowed to interfere with it when the car deck is locked and the vesssel at sea? Spanish ferries and long haul ones have metal cables on the floor which are fixed into sliding sleeves periodically, maybe every eight metres or so, they run the entire lentgh of the ferry, when you strap your bike down to this it influnences the cables and if every body releases or tightens at the same time, all is good(ish) but that never happens, seen the straps being released and heard a bike crash 50 meters away, due to the tension of the cable being let go.Who takes responsibility for that?
The channel tunnel train is even worse, no straps, no tying, no nuffink, and they insist that you park the bike with the front wheel diagonally agasnt the car guide rails, with the side stand on the left of the bike (train travelling forward, standing behind bike), this means that if harsh braking takes place then the bike topples easilly, it it were agcinst the right guard rail it would be 300% safer, I have advised them of this and they wrote a three poage kletter in reply telling nothing.