Whales are near the top of everyone’s list of favorite animals. They’re beautiful and graceful, don’t bother humans, and, if they needed anything to enhance their appeal, they’re endangered. Smart and savvy, whales had been at the top of their food 
chain until about 1800 when humans developed the technology to keep sailing ships at sea for months at a time, and whaling began. (Whaling is a euphemism for the deliberate killing of whales for the oil that comes from the blubber of whales. Whale meat is eaten in scattered areas, but most humans don’t like the taste of any marine mammals, whales included). The real whaling industry today is related to environmentalists who organize whale watches where people enjoy watching these magnificent animals in their natural environment.
Whales on stamps has long been one of the most popular thematic specialties, and the first whaling stamps were issued over fifty years ago. Some collectors collect only whales on stamps. Others make their philatelic quest more interesting by collecting by species. Still others expand the field a bit by adding all sea mammals to their collections and searching for stamps that picture seals, sea lions, and dolphins as well. Philately is your hobby, so you can do as you wish. Many serious stamp collectors maintain traditional “by country” collections such as USA or Great Britain but add more colorful and inexpensive thematic collections that are compliments to their interests outside of stamp collecting. As such, collecting whales on stamps is one of the most popular philatelic thematics that there are.