You look for the dorsal fin on the surface. Calm ocean days are kind of easy to find those fins but if water is not flat, it's a little difficult finding them. One time i thought snorkelers are the dolphins from the distance... Ooops! Hahaha.
Experienced captains could find the dolphins way before I could find every time when I worked on the dolphin-watching boat. My hat off to the captain.
Well, if you are interested in what kind of dolphins lives around Guam, I put some information about them below....
Spinnerdolphins have a long and thin face beak. Their body color is dark gray on the back then the color gets lighter gray and off-white on belly.
They have a very beautiful gradation color. When Spinnerdolphins are babies, the belly is light pink but the color will change to an off-white/cream as they grow up.
They weigh about 45~75kg and measure about 200cm as adults.
They like to hang around close to the island to rest, sleep and play.
Unless the Dolphins are sleeping, they are very playful and seem to be very curious about the boat that comes around them.
They will swim along with the boat and surf the waives that the boat makes. Some times they will jump and spin in the air.
Some Skilled Spinners are able to spin 6 or 7 times in one flip.
They usually will jump 3 or 4 times in a row.
There are many reasons for this behavior. Such as removing parasites from their bod, or to be a decoy to lead the boat away from the rest of the pod.
They will do this when another member is sick or giving birth. But mostly I think they just love to play. :-)
Here is a map of Guam that shows some the favorite places that Dolphins like to hang out.
Their favorite hangouts during the summertime are Double Reef, Tumon Bay, Piti and Asan Cut. But During the wintertime the dolphins seem to like the southern side of Guam, places such as Rizal Beach in Agat, Sella Bay, Cetti Bay and Bile Bay.
Depending on weather conditions such as Tropical depressions or monsoons they may choose other areas to hang around.
Some days we may find them in Apra Harbor but this is rare. A tourist once told me that he has seen spinner dolphins the window of the Atlantis Submarine. Now that's really lucky!
The size of their pods may vary, sometimes there are only 4 to 6 dolphins to be seen or as many as 20 or 30. And sometimes many pods of dolphins will gather together in the same place and there may be hundreds of Spinner Dolphins.
When this happens it's really exciting!!
Nighttime seems to be their main feeding time. They will venture out to Deeper water to feed on squid, shrimp and school of small fish. But during the mid of late summer when Guam has large runs of Big Eye Scad locally known as "Atuli" you can often see Dolphins feeding on them in the day time.
* Book, "Sunsplash" by auther, Bob Odell. * Wikipedia
Spinnerdolphins on Guam and everywhere within the US and its Territories are protected under Federal Law. The law states that molesting or disturbing dolphins in any way is prohibited. Which is why you will not find another that offers swimming with dolphins.
Dolphin watching boats are not allowed to disturb dolphins and most dolphin watching companies know this and keep their distance.
But when the dolphins are not sleeping and are in a playful mood, they will often approach the boat and play in the wake.
Spinnerdolphins are not exactly at the top of the food chain. They have predators, such as Melon Head Whales, Long-finned Pilot Whales, Killer Whales, False Killer-Whales, Pygmy Killer Whales, and Short finned Pilot Whales. When on a Dolphin with tour and any of these other mammals are seen, there will be no Spinnerdolphins. Because they will be hiding some place safe.