Cetacean

Sperm whale

Physeter macrocephalus

IUCN status: VulnerableWidely sought

The largest toothed whale, a deep-diving squid hunter that passes through the deep straits around Alor and neighbouring Lembata, a long-known cetacean corridor. Encounters are almost always at the surface (from the boat) rather than on scuba, and occur mostly during the mid-year to late-year migration window. Blue whales and other cetaceans are also reported in the area.

Max size
Up to about 16-18m (males)
Habitat
Deep offshore water; here in the deep Ombai and Pantar straits

Best places to dive with Sperm whale

rareoccasionalcommonly seenpeak season
Alor
Sighting likelihood by month
MonthLikelihood
Januarynot seen
Februarynot seen
Marchnot seen
Aprilnot seen
Mayrare
Junerare
Julyrare
Augustrare
Septemberrare
Octoberrare
Novemberrare
Decembernot seen

Passes through the deep Ombai/Pantar straits mainly in the mid-to-late-year whale season; typically seen from the surface during crossings rather than underwater.

Sources & last checked

Checked July 2026

This is a researched draft, not yet human-verified. The seasonality and logistics are drawn from the sources below — confirm specifics (permits, fees, closures) with an operator before you book.

Note on the data: Cetacean passage in the Ombai Strait is reported by operators and consistent with the strait's known whale traffic, but no survey data was verified; treat as a surface-encounter chance, not a dive target.