Crossing the Channel? How to get a cheap cabin.
 

This has worked for me a few times on Brittany Ferries Portsmouth - St Malo and once on the old P&O Portsmouth - Le Havre crossings. I'm not saying it'll work everytime, but it's worth the risk if you fancy a bit of comfort. It works best off-season, peak times can mean all the cabins are booked up.

When you book (either online or on the phone) only book a reclining seat. Arrive at the port good and early, and go into the foot-passenger check-in and ask for a shared cabin. They're not sold online, and not offered on the phone (you have to ask specifically), so they're rarely used. You'll pay for one berth only in a cabin of four, but because few people know (knew?) about this, the odds are pretty well stacked that you'll be on your own (you can always ask if there's anyone else sharing anyway). This means you end up with a spacious outside cabin with porthole for about £4 more than the cost of a slippery reclining seat.

Second tip will depend on the boat, or more specifically the key. A lot of the boats have a punched plastic keycard which was found inside the door. You go to your unlocked cabin, throw your stuff on the floor, take a card and go to the bar. So if you've got this type of key, and you've managed to get a shared cabin, get to it as quickly as possible. Flip down all the beds, spread your gear liberally on all four, and leave quickly taking the key with you and locking the door. If anyone else has booked a shared cabin they'll wander along to it, try the door and find it locked. They'll then head back to the purser's desk, to say they can't get in. Because the desk is understaffed and overwhelmed with people asking dumb questions, they won't be bothered to send someone down to unlock the cabin with a master key, instead they do a quick check on their computer to find another empty cabin and give the next sharer this one.

Now of course I've told everyone, so you'll all be doing it, so here's tip number three.

If you're the second person to get to the cabin, and you find your fellow HUBBER in the middle of spreading their gear about say hi, and then explain to them that you're now going back to the purser's desk to say the cabin's locked and you can't get in. Tell your fellow biker you'll meet them in the bar, and wander back slowly to the desk giving them time to leave. You're now like the person just above, and the chances are you'll be alloted a new cabin, all for yourself, so you can snore and fart in peace.

Of course none of this works if you're travelling with your loved one, and want a romantic cabin à deux, as the shared cabins are single sex only (apart from the one time when I found my shared cabin included two nubile German backpackers in the middle of getting changed for the bar, who really didn't seem to care about nakedness in front of strangers and were used to mixed dorms, but that's another story).