Out of the water, Sea Lions look like couch potatoes. Or even like couches. In the water, they're graceful and beautiful. They tend to be big and brown -- whereas seals are black or gray. Sea lions' long flippers give them some mobility on land.

And they're a lot bigger than a seal. A seal only weighs a couple of hundred pounds, but a big sea lion can weigh over a thousand pounds. You often see sea lions lounging around on green buoys.

Although sea lions are found throughout the North Pacific, most of them live in Alaska.

Photo, Lu Lu Belle Cruises & Tours

The Killer Whale isn't a whale at all. It's actually the largest member of the dolphin family. It's very smooth and shiny, with distinctive black and white markings that make it a very pretty animal.

Orcas live in groups, called "pods", some of which stay in the same area, and some which travel.

They're big: 30 feet long and weighing between 5 and 10 tons. They're also fast and strong and have a fierce reputation.

Photo, Lu Lu Belle Cruises & Tours

Harbor seals eat fish, and you'll see them swimming gracefully in the water. On land, it's a different story. They're really too fish-like to be able to maneuver around like most other mammals. So when they're out of the water, they tend to stay in groups for their protection.

Harbor seals are found on icebergs in June when they give birth, and in August when they molt.

Photo, Lu Lu Belle Cruises & Tours

You're sure to see sea otters on a trip into Prince William Sound. They're bigger than their freshwater counterparts and eat huge amounts of seafood. This sea otter is eating a starfish.

Sea otters are covered with very thick fur, and they divide their days between grooming their fur and eating. They live from 10 to 20 years.

Photo, Stan Stephens Charters

Humpback Whales
Humpback whales travel from Hawaii to Alaska every spring. They come here to eat. If you've ever heard a record of a whale "singing", then you've heard what a humpback sounds like. Humpbacks are very large. They're over 45 feet long and weigh 25 to 30 tons. They sometimes feed by blowing bubbles out and making a bubble "net" that traps their feed. They also rise to the surface with their jaw open to catch krill - small floating crustaceans. If you're on a sightseeing trip and see a giant whale's tail disappearing under the water, you've probably just seen a humpback whale.

Gray Whales & Bowheads
Both of these whales are found in Alaska. They both spend most of their time here in the northern seas. The bowhead lives up north year-round, while the gray whale migrates from the Bering Sea in the summer to Mexico in the winter.

Belugas
Belugas are a small white whale that travel in groups. They have a bulbous head. A lot of belugas live way up north, in the Bering Sea. But you're most likely to see a Beluga Whale while traveling down Turnagain Arm, south of Anchorage or from the city of Kenai. Although Belugas are actual whales, they're sometimes called "white porpoises". They travel around in pods.

Dall Porpoises
You may well see black-and-white dall porpoises running alongside your boat out in Prince William Sound, accessible by Valdez, Cordova or Whittier. They're very fast -- and black, with a white belly. The coloring is similar to an orca, but they're smaller - and don't have the very large dorsal fin of an orca whale. They can travel up to 50 mph.

Photo, Lu-Lu Belle Cruises & Tours