Swimming with sperm whales in Dominica is a true bucket list item. Guest author Sam Tibbetts recalls his experiences of swimming with these wonderful creatures…

Swimming with sperm whales in Dominica

A guest post by Sam Tibbetts (photos courtesy of Sam and Patrick Dykstra)

Just over 250m to the north, a feint white spray hung lazily over the placid deep blue Caribbean waters. Camouflaged by the white tops of the softly cresting waves, we could not be sure. However, a moment later, a further distinctive misty blow projected upwards. At which point we knew the game was on and we set off at pace with the hope of our first underwater sperm whale encounter. 

Swimming with sperm whales in Dominica - big head

A safe haven for whales

Our small and now purposively directed boat was located approximately 2km off the coast of the Hurricane Maria ravaged Dominica and beneath us was approximately 300m of water, with the sea floor plummeting dramatically from the rugged mountainous coastline of the Nature Island of the Caribbean.

The Caribbean Sea, in which we were floating, bottoms out at 7,686m in the Cayman Trench. These seemingly fathomless waters are a perfect habitat for giant squid who sculk the shadowy abyss preying on their smaller and weaker colleagues and deep sea fishes. Measuring up to 13m, giant squid have few predators, the exception being sperm whales. These gangly alien-like creatures are an important chewy delicacy, making up around 80% of the sperm whales’ diet. This bounty, combined with Dominica’s relatively undeveloped nature and limited sea traffic is a perfect combination. As a result, the island’s waters are home to several large pods of giant sperm whales who have taken up permanent peaceful residence in the area. This is particularly unusual and special because sperm whales traditionally follow seasonal migrations for feeding and breeding. However, the Dominican whales feed, breed and give birth all in the same area.

To their great credit, the Dominican Government takes considerable care to ensure the whales are not disturbed. Only one boat is licensed to take swimmers out on any day and only two swimmers and guide allowed in the water at any time. The extra benefit being that we had the whales to ourselves that week.

Swimming with sperm whales in Dominica - dolphons

It’s not only whales that benefit from the calm Dominican waters; dolphins also proved to be a regular sight

Searching for whales

However, despite the fact that an adult male sperm whale can measure up to 22m, it is by no means easy to spot them in the vast open sea. Particularly as they spend large amounts of their time hunting hundreds of metres below the surface. Sperm whales have been known to dive as deep as 2,250m in search of their prey, holding their breath for a lung bursting 90 minutes. This places sperm whales second only to the elusive Cuvier’s Beaked Whale, which is known to dive a body imploding 3,000m (or 3.5 Burj Khalifas).

Swimming with sperm whales in Dominica - Dom Sperm Whales

Sperm whales are naturally wary and, at times, cautious and timid. This requires them to be approached with care. If spooked, they will drop vertically, rapidly disappearing into the endless blue with a few gentle beats of their huge triangular flukes. 

The goal is to determine the whale’s rough direction of travel and then direct the boat to one side, dropping in the water around 40m ahead. After swimming a further 15m to position yourself, with luck the whale should hopefully drift about 5m past. There is a real art to the approach as, if you position the boat in front of the whale, it will dive. Equally, if you swim in front of the whale, it will dive.  A further element of jeopardy is added by the fact that even a slight change in the whale’s direction of travel can either require a significant amount of additional swimming, or alternatively you can end up in an unintended face off with an animal the size of a bus. 

Swimming with sperm whales in Dominica - sam and sw

Furthermore, each whale very much has its own character and mood. A few whales will permit only the briefest of glimpses before swiftly melting away. However, others are more relaxed and curious and we had a number of spectacular encounters that developed in a crescendo over the 5 days on the water, a few of which I describe below.

Swimming with sperm whales in Dominica: Day 1

Despite all best intentions and preparations, when you hear the signal to “Go! Go! Go!”, it is invariably a mad and frenetic fluster as you collapse into the water and attempt to orientate yourself and the whale whilst avoiding sucking in too much salt water from your flooded snorkel. However, one drowned camera aside, the process became more fluent over the week. 

Swimming with sperm whales in Dominica - momma with baby

Our first day started really very well with a steady swim alongside a mother and her calf.  However, remember my earlier comment about how the goal is to avoid a head on encounter but also the unintended consequences of a slight change of course by the oncoming whale. Well…

Before I go into that, perhaps a bit more detail about sperm whales for context.  Some key facts:

  • The “sperm” part of the name is a truncation of “spermaceti whale”. Spermaceti, originally mistaken as the whales’ semen, is the semi-liquid, waxy substance found within the whale’s head and was a prime target of the whaling industry due to its use in oil lamps, lubricants and candles.
  • A sperm whale’s head forms up to one third of the length of the whale’s body and contains the largest brain of any animal on Earth, more than five times heavier than a human’s. At the top of the whale’s skull is a large complex of organs filled with the spermaceti. The purpose of this complex organ is to generate powerful and focused clicking sounds, which the sperm whales use for echolocation and communication, with vocalization as loud as 230 decibels underwater (a jet take-off at 25 metres is 150 decibels).
  • The sperm whale is the largest toothed predator in the world with its protracted thin lower jaw containing a strip of giant conical teeth measuring approximately 18cm (7 in).
  • Mature males average 16m in length with their heads reaching up to 3.5m in height and the fluke up to 4.5m (15ft). They weigh in at 41,000kg.
  • Females average around 11m and average a significantly trimmer 14,000kg. 
  • If, like me, numbers make you go crosseyed and you struggle to picture what the above looks like, please use my handy modern-day  London Routemaster Double Decker Bus visionary comparison tool.
  • In brief, the latest incarnation of the famous red double decker that is regularly seen plying the roads of London measures 11.23m and weighs 12,650kg. 
  • With this in mind, the average female, measuring 11m and weighing 14,000kg is about the same length as a Routemaster and over a 1,000kg heavier.  The average male is almost twice as long as the bus and more than three times heavier. 

At this point, it is worth diverting back to the unintended route change on day one. In the middle of finning to the zone where we thought the sperm whale was heading our experienced guide, Patrick Dykstra, signalled for us to stop abruptly. We held still as it turned out the female whale had changed its course. She was heading directly towards the spot where we were cautiously and expectantly bobbing.

Within seconds, a small hazy grey apparition emerged out of the foggy blue waters. It steadily grew in size and definition until a huge 10m  female filled our vision, stopping only 7m away. She was curious to understand the nature of the colourful, strangely shaped and motionless (albeit ridiculously excited) floating obstacles. Raising her head and jaw bone, she proceeded to direct a series of deliberative and clearly audible clicks at each of us in turn. Evidently determining that we were a non-hazardous impediment, she slowly turned her head to swim on. Passing at a distance of no more than 3m, she thoughtfully observed us with her small sunken right eye. 

Swimming with sperm whales in Dominica - sam and sw 2

Swimming with sperm whales in Dominica: Day 4

The second and third days offered further good encounters. Day three included an exceptionally rare topside viewing of a relaxed pod of almost mythical Gervais beaked whales. 

However, day 4 stands out for our encounter with the Don Juan of the sperm whale community.  After a relatively fruitless morning, Patrick sent up his drone to scout what appeared to be a series of feint blows further out to sea.  Huddling around the video screen, the drone dramatically revealed a huge 22m male. Behind him followed a pod of 14 females and their calves, spread out in a Red Arrow v formation. What was particularly striking was the fact that the male’s skin was considerably lighter than the females, giving him a ghoulish appearance as his giant outline rippled in the water.

Swimming with sperm whales in Dominica - Dom Group

With this large and preoccupied pod heading in our general direction, we waited patiently before slipping into the water as they approached.  With so many whales, we ended up dispersing in different directions. Having swum around the back of the boat I once again found myself in the direct path of the whales, including the enormous alpha male. I therefore once again stopped still as the pod descended upon me with the alpha male dipping down and then twisting to one side to watch me as he glided slowly by, only metres below. Four females were close behind, accompanied by an excitable soundtrack of rapid fervent clicks.  Rising back up the surface it felt like his enormous (more than double LeBron James length fluke) was almost within touching distance leaving me transfixed by awe and yet again impressed by the considerate and curious nature of these amazing animals. 

Swimming with sperm whales in Dominica - Male picture

Swimming with sperm whales in Dominica: Day 5

Day five provided the aspirational (and rare) encounter that we all hoped for, but knew was far from guaranteed. This was the opportunity to swim with a stable pod of sperm whales as they rested near the surface. To his great credit Patrick managed to deliver this on our final day at sea. Skill, judgment and perseverance playing as important part as luck. 

The sea was significantly rougher that day with the ragged white crests the high rolling swell making it harder to identify the whale blows. Once in the water, orientation was also far more difficult. The high waves limited top side visibility to no more than a few metres, forcing us to rely on directions from the boat.

Despite this we came across what we had been hoping for the whole week, a stable pod of around 12 whales. This was particularly remarkable as the whales were resting below the surface with almost no topside indication of their presence. I was unaware of what I was about to encounter when I dropped back into the water (which I have to admit I did somewhat reluctantly due to the swell). It felt a bit like pulling on a loose cotton thread on your shirt. 

Swimming with sperm whales in Dominica - vertical

At first it appeared that there were only a couple of whales. But as my eyes adjusted and I investigated further the scene escalated surprisingly rapidly. Immediately in front of me, near the surface, was a mother with her busy calf. Both beyond and below them, I could now also make out the vague outlines of a number of other whales. Some 10m below my fins four adult whales were resting in a vertical position. A steady fine stream of bubbles emanated from their blow holes, heading towards the surface. Amongst this group was a mother suckling her young calf, which came up to investigate after filling its belly which nutrient rich milk.

Swimming with sperm whales in Dominica - Family

We had the great privilege of spending over 45 minutes with this calm group before finally calling it a day. Giving the whales some space and to get some air back in the lungs. 

Swimming with sperm whales in Dominica - P2260005

I visited Dominica with Picture Adventures in early March 2018. Led by the irrepressible Patrick Dykstra, the experience is an exceptional reminder of the wonders of our ocean and the intelligence of life beyond our own.

About the Author

When he’s not stuck in the office, Sam can be found gallivanting around the globe in search of adventure and wildlife. He’s particularly passionate about about spending time with animals in the wild, on their terms. Check out Sam’s Instagram account for a wonderful array of wildlife photography. Warning: may cause a serious case of wanderlust. 

By SAM TIBBETTS

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