Keith's rough crossing of the Bay of Biscay reminded me of another rough ferry crossing story ...
Being a regular traveller on the ferry between Tasmania and the north island of Australia (across Bass Straight), I've had a few rough crossings, but nothing too drastic. Bass straight can get bloody rough though. It has a notorious reputation and there are heaps of shipwrecks out there.
In the old days the tying down of bikes was done inadequately (by the ship's crew) with bits of sisal rope. Damage to bikes was commonplace. Nowadays they use proper motorcycle tie-downs, but I've always done my own tying down, or at least be there when the crew does it. Ships crew are generally OK with that.
The roughest Bass Strait crossing I've heard of was when my brother Tim was on the boat (I wasn't on that trip). That was back in the bad old days (maybe 30+ year ago) when they used rope to tie bikes down. Usual method employed by the crew was simply to throw a rope over the seat of the bike and pull it down tight with a truckies hitch. Pretty useless really.
Now on that occasion, Tim was aware that the weather forecast was bad, and being a seasoned traveller on that boat (unlike the other tourists) he knew how bad it could get. So he tied his 3C down himself with a spider's web of rope. His bike was in the middle of a row of bikes parked side-by-side. The other bikers didn't heed his warnings and simply left it to the crew to secure their bikes. So he grabbed a couple of extra bits of rope and tied a line onto the opposite sides of the bikes either side of his to stop them falling against his bike. If they did happen to fall over, they could only fall the other way.
Anyway, it as a very rough overnight crossing, with lots of banging, crashing, scraping and screeching coming from the vehicle deck. Going down to the vehicle deck in the morning revealed the carnage. Cars had broken loose and had been crashing into each other all night. A semi-trailer had toppled over, crushing the cars that were parked beside it, including a camper van that was pancaked. All of the bikes had fallen over like dominoes - all except Tim's 3C. Because of his preventive guy ropes on the bikes either side, the domino effect fell away from his bike on both sides, leaving his as the lone standing domino in the middle!
He was able to ride off while everyone else was extracting their bikes from the tangled mess. The only damage to Tim's bike was a small hole chafed through the seat vinyl where a crew member had done the stupid rope over the seat job. That hole is still there today, usually covered by a bit of black gaffer tape these days. Part of the bike's extensive patina. I think that's why he likes to leave his bike in unrestored condition. Every ding, scratch or mark has a story to tell!