If you're contemplating a voyage across the Pacific from British Colombia to, say, Australia and stopping along the way to practice your nursing skills... I would say Go For It!
Medical professionals are in short supply throughout the world and if you were to drop anchor in a tropical lagoon and walk up to the local clinic or hospital I am sure you would enjoy a warm reception! If you let it be known that you'd like to stay a while and help keep the local population healthy - the officials will very likely arrange a working visa to be issued in record time. You might be expected to study in order to obtain local qualifications... or you might be asked to share your knowledge and train the local nurses in an attempt to bring them up to your lever of higher education.
I've met many medical professionals of countless nationalities out here in the cruising community who seem to find work wherever they go and whenever they want it. Some have even wound-up settling into management positions. And I personally know Australian, Canadian, British, French and Philippino cruisers who've been granted working visas to practice their skills in California & Hawaii and made a fast bundle of US Dollars to add to the kitty while working in cutting-edge medical facilities.
A cruising nurse can find work in just about any port they wish to linger in. Pay varies from little to lots but I believe the reward is being able to help people while enjoying an in-depth understanding of another culture. You may not always make a lot of money but you'll be able to really get to know a place without it costing you anything but time.
I've always found it easy to find honest work whenever I've wanted to set the hook and stay in one place a while by letting those in authority know that I'm willing to share my mechanical knowledge and help in any way I can. I've been funding this great adventure for the past 16 years by sailing a while and then stopping and working a while. I'll never be rich in pocket but I live a rich life. It's a great feeling to gain the trust of strangers and know how much they appreciate what you're doing. It's a fine way of enriching the lives of others and yourself.
Don't worry about chasing foreign qualifications - they will come to you freely while cruising as long as you're honest and willing to share what you know.