It's a very good topic... thks Peter
It used to be quite easy to travel by boat... unfortunately, this was 10 to 15 years ago (maybe 20?)
It is still possible, but either it costs a lot of money or you need time and patience.
That said, there are still people who find a way...
Here are the options:
1) Freight and cargo: this is the expensive option and you usually need a reservation. (still cheaper than a cruise) $50 to $130 a day / person and here are a couple of links you can look at:
http://freighterworld.com/ and
http://www.reederei-nsb.de/site_frachtschiffreisen_en/?node_id=22) You can still show up "uninvited" at the departure of the cargo boat and try to work on board in exchange for transportation, but it is unlikely it will work, especially after all the regulations post 9/11
3) In my opinion, the best way - but it takes a while - is to hang around at the marinas, ports and anchorages and offer assistance in preparation to the yachts and mention that you are looking for a ride and would like to join a boat for such and such a destination. All the cruisers are in close contact with each other so you might end up being recommended. Make an ad with a phone number where you can be reached and leave it everywhere - in port offices, yacht clubs, boating shops, and area marinas. Be useful, helpful, reliable and friendly. I have a bicycle traveler friend who always finds ways to cross oceans with private sailboat owners. He said you just have to be patient - he usually puts up his tent near the marina until he finds someone. But he has a lot of time and he is very likable...
4) Of course, if you have experience as a skipper it makes things much easier! as there are crews out there looking for people to work on larger yatchs or people just skippering a sailboat from A to B and looking for some help.
www.workonaboat.com is a good place to look if you have experience.
My friend told me this is a pretty good forum to get info or to look for crews looking for help... I didn't check myself...
http://www.cruiserlog.com/forums/Sorry, it's not much, but traveling by boat nowadays is not easy... especially with a bicycle and all the panniers!