If you live in a city which offers dinner cruises, sight seeing cruises, ferry service, day boat trips - even private boats - try to get some work onboard these vessels. Any catering, banquest, hotel work will serve you well as experience.
And no, playing with your red boat in the bathtub, doesn't count!
Keep in mind that cruise ships are just like little cities, so just about any job you can think about exists on a ship. Having said that, many positions are always earmarked for certain nationalities. Usually deck/engine crew are foreign nationals, the officers are usually but not exclusively from UK, Italy, Greece, Portugal, USA, Canada. If you are a cadet in training, you may be from Canada, USA, UK - just about any country.
The bar department crew can be from a number of countries - but it is looooong hours and mostly tips - monthly salary is very low. The same goes for dining room staff. Bartenders do a little better and many are from UK, Caribbean Islands, some from USA. Room attendants/housekeeping make pretty much straight tips only with a small monthly stipend or salary - once again, mainly crew from overseas.
My recommendation is to focus on Front Desk/Purser Dept, Shore Excursions, Shops/Boutiques, Casino, Photogs, Cruise Staff, Youth Staff, Future Cruise Sales, Port Shopping Guide, Bands/Musicians, Fitness/Spa, Internet Manager, Golf Pro, Show Dancers, Captains Circle/Repeat Cruisers/VIP Concierge.
Regarding river cruises, there is also a google ad link here somewhere, www.EuropeanRiverCruises.com - check it out to see the various river cruise companies in Europe. The most notable is Viking River Cruises.
