The soft case took the weight of the bike as it fell against the side wall of the Ferry and prevented it falling over completely. The rubberised moulded bottom of the case cushioned the impact until I managed to lift the bike back onto its stand.
All 4 plastic clips also held. Was amazed.
Obviously lucky the bike was close to the side wall of the Ferry and nothing else fouled on the boats structure. Real impressed with the strength of this rear bag. Can recommend this item.
Moral of this story - Avoid parking on a sloping floor on Ferries , even if thats where the attendant wants you to park!
About to leave for Scotland ...
(note quick release clips at base of bag. It also has a fully waterproof liner, handy top pouch and carrying strap. Also expandable. )

Rear view. (Near Ullswater, Lake District on route to Scotland)

(Will be posting some other Scotland photos in Photo Forum tonight/tomorrow to give you non-UK guys and gals a taster)