Recently, I was on a trip shooting cetaceans with a group. I'd assumed everyone who was going to shoot underwater would have to apply for permits from the country's Ministry of Tourism and Defense (Navy) and Coast Guard as I did. To my utter surprise, there were several groups of photographers who did not have permits and tried to fly under the radar because of intermittent enforcement from the said country's Navy/Coast Guard.
I bring up this issue because it's important to be totally legal in our activities because of several factors:
1. Respect for local government/people: As a visitor, it's important to show respect by applying for all the permits necessary to legally take images. It's not important that in the entire time I was there, no one checked the permits. It's not your country and there are laws to be followed. It's common courtesy really.
2. Permits control the number of people interacting with wildlife, so there isn't a free for all. For example in Sri Lanka, there's a general lack of rules for whale viewing, so much so that competing operators claim the "other" boats are harassing the whales. Still, there's a growing number of people thinking swimming with whales is totally easy and promoting them without actually having any permits. It's not only illegal but also detrimental to the health of the population of whales in the area. One only has to look at Ruruutu in Tahiti to see the effects of badly managed whale watching. The population of humpbacks have dwindled over the years.
3. Most publications and competitions want permits: The most important reason for those intending to publish their photos for competitions and publications is that many competitions like the BBC/NHMC Wildlife Photographer of the Year requires permits to prove the shots were taken legally. This protects you if someone raises doubts on the legitimacy of your images, including the authorities from the country of origin. Your reputation would be pretty tarnished is the legitimacy of your photographs come into question.
Let's also be real in that most of us want to go to countries where there are lax rules for engaging in these sort of activities. Ever try getting a shooting permit for Blue/Grey whales in California and Mexico? It isn't easy at all! So many go to places where the rules are lax. However, that should not mean that one should flout all rules because they can afford it. For those who try to fly under the radar because they are too lazy to get the permits or think they are above the law, don't be surprised if you get called out publicly. I hope you don't get caught, but why take the risk?