The Blainville’s Beaked Whale (Mesoplodon densirostris) is one of the most mysterious and rarely observed cetaceans in the Atlantic Ocean. Known for its incredible deep-diving abilities and elusive behavior, this species occasionally appears during Ontales Whale Watching tours in Madeira — offering unforgettable encounters for lucky guests.
The Blainville’s Beaked Whale (Mesoplodon densirostris) is a true whale, not a dolphin. While dolphins belong to the family Delphinidae, beaked whales are part of the family Ziphiidae. Unlike most dolphins, Blainville’s Beaked Whales are larger, shy, and spend much of their time in deep offshore waters, surfacing only briefly — making sightings during Ontales tours a rare and special experience.
“This whale can reach depths of 1,400 meters or more and stay underwater for over an hour.”
The Blainville’s Beaked Whale belongs to the family Ziphiidae, a group of deep-diving whales known for inhabiting offshore waters far from the coast. They are recognized by their streamlined bodies, small dorsal fins, and distinctive beaks.
Scientific name: Mesoplodon densirostris
Appearance: Long, narrow beak; arched lower jaw with protruding teeth (in adult males)
Coloration: Grey or brownish with scars caused by social interactions and parasites
Distribution: Worldwide in deep, warm, offshore waters
Behavior: Extremely shy and difficult to approach
Their secretive nature makes sightings rare — which is why observing them with Ontales is a truly exceptional experience.
One of the most common questions people ask is about the Blainville’s Beaked Whale size.
Here are the essential measurements:
Length: 4.5–5.5 meters (up to 18 feet)
Weight: Around 800–1,000 kg
Males vs. Females: Males tend to be slightly larger, with more prominent tusk-like teeth
Despite their moderate size, they are among the world’s greatest marine athletes — capable of deep dives that rival sperm whales.
Blainville’s Beaked Whales are extraordinary divers. They can reach depths of 1,400 meters or more and stay underwater for over an hour. Most of their life takes place far below the surface, which explains why sightings are so rare.
Their diet primarily consists of:
Because they spend so much time underwater, brief surface moments are both precious and spectacular for observers.
Madeira’s deep offshore waters create ideal conditions for this species. The underwater topography — steep drop-offs and submarine canyons — provides access to the deep zones where these whales hunt.
Ontales navigates along natural deep-sea trenches
Guides are trained marine biologists experienced in identifying rare cetaceans
The calm Madeira climate increases chances of spotting subtle surface activity
While sightings are never guaranteed, Ontales has documented encounters that give guests a glimpse of this exceptional deep-diving whale.
Ontales guides look for:
Slow, careful surfacing behavior
A long, distinct beak
A small, slightly curved dorsal fin placed far back
White scars and scratches along the body
Males with tusk-like teeth sticking out from the lower jaw
Because they avoid boats and remain quiet at the surface, professional observation is key — one of Ontales’ strengths.
Spotting this species is considered a highlight for any whale watcher, marine biologist, or wildlife enthusiast. Reasons include:
They are one of the least observed whales in the world
They spend most of their lives deep underwater
Their unique morphology makes them unlike any other whale
Encounters offer insight into rarely studied deep-sea ecosystems
Guests who witness one often describe it as a once-in-a-lifetime moment.
Ontales creates responsible whale watching experiences that respect the natural behavior of all marine species. While Blainville’s Beaked Whale sightings cannot be predicted, Madeira’s rich ecosystem and Ontales’ expert guidance make it possible to encounter these elusive deep-diving giants.
Explore the ocean with purpose — and maybe meet one of the Atlantic’s most mysterious whales.
Other Marine Wildlife You Might See on Ontales Tours
Alongside Blainville’s Beaked Whales, guests on Ontales whale watching tours frequently encounter a variety of fascinating marine species:
These are shy and peaceful whales. Blainville’s beaked whales spend most of their time under water. They are relatively small although they can reach 6 metres. Long and slim, the colour of their body can be from dark grey to dark brown. Their head ends with a beak. Males may feature 2 visible teeth in the lower jaw. Their estimated lifespan is unknown. They are exceptional divers: up to 1.1 hours and almost 1500 meter deep! They do so in order to feed on cephalopods and fish. We can usually see them in groups of 3 to 7 individuals. Possible marine predators: Orcas and sharks although the main threat remains the direct capture by fishing gear, collision with boats and ingestion of plastic.
