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Ocean Calling

Ocean Atlas · Pacific

Pacific

Guam

A US island in the western Pacific with reef walls, WWII wrecks and green turtles. Watch and dive only. No mammal swims.

Green turtle
Green turtle, found in the waters of the wider region · Photo: James Thornton on Unsplash
Story only

Story only, for now. We love learning about this place and its ocean, so we share its story here and do not sell trips yet. Checked by Ocean Calling on 6 Oct 2026. Sources: Marine Life Viewing Guidelines: guidelines and distances, NOAA Fisheries; UOG Sea Grant continues critical sea turtle conservation efforts, University of Guam; Piti Bomb Holes Marine Preserve, Wikipedia.

Why: Guam's reefs and bays are home to green and hawksbill turtles, which nest on the island's beaches mostly from about April to August, and wild spinner and bottlenose dolphins live in the waters off the island. Marine mammals and turtles are protected by US federal law (the Marine Mammal Protection Act and the Endangered Species Act), and the national guidance is to stay 50 yards from dolphins and turtles and 100 yards from whales, never to swim with, ride, touch or feed them. Guam has five marine preserves, including Piti Bomb Holes, set up by Public Law 24-21 in 1997. We share the island's turtle and reef story and watch from a respectful distance, never swimming with or touching the animals.

Why Guam

People come for Tumon holidays and for scuba: Blue Hole, Piti Bomb Holes, Gun Beach and Apra Harbour wrecks. Turtles are the honest headline animal. Spinner dolphins and humpbacks are watch-only under US MMPA. Ocean Calling shares Guam as a story for now.

Conservation-led. Ocean Calling guests never chase, touch or bait animals.

IndonesiaChinaTaiwanPhilippinesMalaysiaBruneiGuam, Guam

When to go

Dec-Jun is usually the clearer, drier window on the west coast. Jul-Nov is wetter with typhoon risk.. Timing changes by place and by animal, so check each place below.

We share this place as a story so you can learn. There is no Ocean Calling trip.

Our ethics check

Can we travel here ethically?

Story only

We tell the story. We do not sell a trip here.

Checked 6 Oct 2026. Places change, so we look again every year.

Sources for this check
The story

Where in Guam

We share these places as stories and research notes. We do not offer or sell trips here.

Guam

Story only

Reef walls, the Blue Hole and harbour wrecks. Green turtles are often on the reef. Do not touch. Mammals stay on the boat.

Also seen: Green turtles on the reef (look, do not lift), Spinner dolphins from a boat if they pass

When: Dec-Jun. Dry months are usually clearer on the west coast. Typhoon risk rises from August to November. No sighting is promised.

Animals

Animals recorded in Guam

Tap an animal to learn how it lives, where it travels and how to meet it respectfully.

Land animals
Green turtle resting on the reef, shell and head pattern in sharp detailGreen turtleChelonia mydasSeen in 103 countries in the AtlasLeast ConcernTwo spinner dolphins swimming over sand in clear waterSpinner dolphinStenella longirostrisSeen in 66 countries in the AtlasLeast ConcernHawksbill turtle swimming, pointed beak in profileHawksbill turtleEretmochelys imbricataSeen in 88 countries in the AtlasCritically EndangeredCommon bottlenose dolphin swimming over a seagrass bedCommon bottlenose dolphinTursiops truncatusSeen in 89 countries in the AtlasLeast ConcernTwo blacktip reef sharks swimming over sunlit sand in turquoise waterBlacktip reef sharkCarcharhinus melanopterusSeen in 38 countries in the AtlasVulnerableBryde’s whale surfacing and exhaling in deep blue open oceanBryde's whaleBalaenoptera edeniSeen in 36 countries in the AtlasLeast ConcernSperm whale mother raising her fluke beside her calf off DominicaSperm whalePhyseter macrocephalusSeen in 114 countries in the AtlasVulnerableWhitetip reef sharks resting stacked in a reef creviceWhitetip reef sharkTriaenodon obesusSeen in 43 countries in the AtlasVulnerableScalloped hammerhead shark cruising in deep blue Red Sea waterScalloped hammerheadSphyrna lewiniSeen in 57 countries in the AtlasCritically EndangeredSchool of bigeye trevally swirling near the seabed at AmedBigeye trevallyCaranx sexfasciatusSeen in 48 countries in the AtlasLeast ConcernShort-finned pilot whale surfacing off Tenerife with the island behindShort-finned pilot whaleGlobicephala macrorhynchusSeen in 43 countries in the AtlasLeast ConcernHumphead wrasse swimming over a coral reef in Raja AmpatHumphead wrasse (Napoleon wrasse)Cheilinus undulatusSeen in 34 countries in the AtlasEndangeredGreat barracuda cruising in open blue water, showing jagged teethGreat barracudaSphyraena barracudaSeen in 84 countries in the AtlasLeast ConcernWhite-spotted eagle rays gliding over coral at Heron Island, Great Barrier ReefSpotted eagle ray (ocellated eagle ray)Aetobatus ocellatusSeen in 28 countries in the AtlasEndangeredFalse killer whale surging through blue water off Rota, Mariana IslandsFalse killer whalePseudorca crassidensSeen in 41 countries in the AtlasNear ThreatenedBluestreak cleaner wrasse with black stripe and blue tailBluestreak cleaner wrasseLabroides dimidiatusSeen in 51 countries in the AtlasLeast ConcernCuvier's beaked whale surfacing, pale scarred head and small dorsal finCuvier's beaked whaleZiphius cavirostrisSeen in 42 countries in the AtlasLeast ConcernMelon-headed whales leaping together through a splash of white waterMelon-headed whalePeponocephala electraSeen in 22 countries in the AtlasLeast ConcernPantropical spotted dolphin gliding at the calm ocean surfacePantropical spotted dolphinStenella attenuataSeen in 56 countries in the AtlasLeast ConcernRound ribbontail ray swimming over rocks at Santa Cruz, GalápagosRound ribbontail rayTaeniurops meyeniSeen in 18 countries in the AtlasVulnerablePortuguese man o' war floating with purple crest off Pico, AzoresPortuguese man o' warPhysalia physalisSeen in 36 countries in the AtlasNot EvaluatedPale reef stonefish resting between anemones in KwajaleinReef stonefishSynanceia verrucosaSeen in 25 countries in the AtlasLeast ConcernClown triggerfish with big white spots over reef in the Coral SeaClown triggerfishBalistoides conspicillumSeen in 29 countries in the AtlasLeast ConcernTitan triggerfish swimming over a reef slope in blue waterTitan triggerfishBalistoides viridescensSeen in 40 countries in the AtlasLeast ConcernPicasso triggerfish with painted pattern over sand in the MaldivesPicasso triggerfish (lagoon triggerfish)Rhinecanthus aculeatusSeen in 41 countries in the AtlasLeast ConcernRed lionfish with spread fins over sand in Dauin, PhilippinesLionfish (red and common lionfish)Pterois volitans and Pterois milesSeen in 80 countries in the AtlasLeast ConcernDay octopus beside a coral head on a sandy Red Sea reefDay octopusOctopus cyaneaSeen in 35 countries in the AtlasLeast ConcernBlack noddy perched in a shrub on Tern Island, French Frigate ShoalsBlack noddyAnous minutusSeen in 37 countries in the AtlasLeast ConcernAdult brown booby standing on a rock with its bill open against blue sky, PrincipeBrown boobySula leucogasterSeen in 104 countries in the AtlasLeast ConcernClose view of a red-footed booby head with blue, pink and red bill and throat skin among green leavesRed-footed boobySula sulaSeen in 91 countries in the AtlasLeast ConcernGiant trevally swimming close to a coral head, with small reef fish in blue water behind itGiant trevallyCaranx ignobilisSeen in 33 countries in the AtlasLeast ConcernRobber crab on rough coral rock with bent legs and large claws, in daylightRobber crab (coconut crab)Birgus latroSeen in 17 countries in the AtlasLives on landVulnerableGreat frigatebird in flight, with long angled wings and a forked tailGreat frigatebirdFregata minorSeen in 44 countries in the AtlasLeast Concern
Curious?

Why this is a story, not a trip

Read our ethics check above. If you would like to talk about it, Rocío is happy to explain.

Ask RocíoBack to the Ocean Atlas

Also in Pacific
American SamoaAustraliaCook IslandsFijiFrench PolynesiaKiribatiMarshall IslandsNauruNew CaledoniaNew ZealandNiueNorfolk IslandNorthern Mariana IslandsPapua New GuineaPitcairn IslandsSamoaSolomon IslandsTokelauTongaTuvaluVanuatuWallis and Futuna

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