Blackwater Blankets

Blanket assertion: An grownup feminine blanket octopus demonstrating how the species received its widespread title, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


Octopuses have all the time been a extremely ranked topic for underwater photographers, however there are ranges to their attraction, with sure species gaining extra consideration than others. If there was an Octopus Corridor of Fame, earlier chart-toppers would absolutely embody the venomous magnificence, the blue-ringed octopus; the shape-shifting mimic octopus; and the extra not too long ago described wunderpus, which has one of the best scientific title of all cephalopods—Wunderpus photogenicus.

In the previous few years, a brand new contender to this crown has emerged, punching her approach to the highest spot. Meet the blanket octopus—Tremoctopus sp.—whose attraction is twofold: They’re uncommon and really elusive. Each photographer desires a photograph of a topic that’s not generally encountered to allow them to showcase to their mates! In the end although, it’s the sheer great thing about this exceptional cephalopod that has propelled a meteoric stand up the rankings. When a blanket octopus unfurls her ludicrously vibrant blanket, it’s a sight to behold. There may be nothing that compares to the gaudiness of this supermodel’s outfit; we’ve a brand new GOAT—Biggest Octopus of All Time!


The diminutive and far much less flashy male blanket octopus, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, f/32, 1/250s, ISO400)


The explosion of blackwater diving over the past decade has seen the variety of encounters of this species improve from “as soon as in a blue moon” to “occasionally.” To place this into perspective, within the lots of of blackwater dives I’ve accomplished, I’ve encountered the smaller male blanket octopus on maybe six dives, the more-coveted females on solely 4 dives—three of those being sightings from a single red-hot week in Anilao in April 2023. These aren’t an on a regular basis encounter!


Blanket Info*

Blanket octopuses are a pelagic species, residing their total life cycle in open water. This makes them laborious to search out and even tougher for scientists to review of their pure setting. There are 4 species within the genus:  

  • Tremoctopus gelatus: a gelatinous deep water species from tropical and temperate waters
  • Tremoctopus robsoni: identified from the waters off of New Zealand
  • Tremoctopus gracilis: palmate octopus discovered within the Indo-Pacific area
  • Tremoctopus violaceus: violet octopus discovered within the Atlantic

Their life cycle can last as long as 5 years, exceptionally lengthy for a cephalopod, and so they have been noticed looking in the identical space for an prolonged time frame. Being a pelagic animal means they don’t make a burrow within the sand or create a house like different octopuses do. These octopuses mate, hunt, feed and thrive within the open ocean and may roam from the depths of the darkish zone to the floor, actually masters of their open ocean area.

Distinctive in look and distinctive in behaviour, the Tremoctopus is proof against the lethal nematocysts of many cnidarians, together with the person o’conflict jellyfish. It’s reported that juvenile Tremoctopus rip the stinging tentacles from the jellyfish after which maintain them with their lateral arms, whipping them about to sting their prey and maybe to guard themselves. Many photographs present the trailing tentacles and clearly illustrate that that is certainly a standard habits.

*These information are an abbreviated excerpt from Mike Bartick’s wonderful e book, The World of Blackwater, which is important studying for any blackwater fanatic. It’s accessible on Apple Books and Gumroad.


{A partially} unfurled feminine blanket octopus, Lembeh Strait, Indonesia (Nikon D500, Nikon 60mm f/2.8 macro, f/32, 1/250s, ISO400)


The sexual habits can be fascinating. The male of the species displays the next diploma of dimorphism than any animal but to be found. The feminine can measure as much as six-and-a-half ft in size, whereas the males solely attain a dimension 20mm—lower than an inch—a dimension/weight ratio of as a lot as 10,000 instances! Male Tremoctopus makes use of a specialised arm referred to as the hectocotylus, like different male octopuses, which incorporates its sperm pack. The male solely then wants to the touch the feminine with this specialised arm, because it immediately sticks to her after which snaps off—maybe with out her even figuring out.

The arm then creeps down or one way or the other finds its means into the ovum of the feminine the place she crushes it, releasing the sperm and fertilizing her eggs when the time is correct. Hatching is intermittent. The male, like different octopuses, having accomplished his life’s work, now dies. Nevertheless, the feminine nonetheless has an extended life forward, brooding and caring for her eggs, till she lastly dies from hunger very similar to different, extra acquainted octopus species.

Tremoctopus will get its widespread title from the blanket that it may possibly shortly unfurl and retract. The feel of the blanket seems like an exaggerated model of the webbing {that a} widespread octopus has and makes use of to net over their prey when looking. Nevertheless, these guys deploy the blanket to make themselves look larger and maybe to hunt and catch crustaceans or different cephalopods just like the paper nautilus. The skinny membrane is colourful and ocellated, very similar to the feathers of a peacock, with a pink, purple-green hue. They’ll additionally detach their webbing to ensnare a would-be predator or to evade in addition to ink.


A big feminine blanket octopus cruising by the night time, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


The place to See

As already talked about, you’ll be able to encounter blanket octopuses in a wide range of areas, although not all areas have dive operations providing blackwater diving. By far the commonest vacation spot for them to be seen is Anilao within the Philippines. This can be partly attributable to extra operators providing blackwater dives on this space, which in flip places extra eyes on the market to search out them.

Different Indo-Pacific areas I do know they’ve been seen are Romblon within the Philippines, and each Lembeh and Ambon in Indonesia. On rarer events, blankets might be seen on blackwater dives within the Gulf Stream, out of West Palm Seaside, Florida. I’ve additionally learn of them being seen off the Nice Barrier Reef on the east coast of Australia, the Gulf of Mexico, and the Mediterranean Sea. 


Blanket Habits

If you end up on a dive and a blanket octopus turns up, be ready for potential chaos. They’re very fast after they need to be, so it’s time to shift up a few gears to stick with them. Not like people, blanket octopuses shouldn’t have any of the constraints of equalizing or decompression illness, so can quickly dive into the depths, leaving you with painful ears, or extra dangerously, trigger a diver to ascend at speeds means quicker than are protected.

Care have to be taken and particular consideration paid to no-decompression limits, air consumption, and most working depths in the event that they head downwards. In the event that they shoot for the floor, divers have to be additional cautious with ascent charges. If the latter, it’s a lot safer to cease capturing, use your dive mild to maintain observe of them whereas ascending at a standard velocity, after which recommence capturing when you’ve got caught again up.


A feminine blanket octopus with the blanket retracted, Lembeh Strait, Indonesia (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


Should you hit the jackpot and get a relaxed supermodel that fortunately poses for a number of photographs, benefit from it—you’ve discovered gold! Use this chance to shoot at totally different angles and seize totally different poses, however be ever able to seize the cash shot if the blanket is revealed. In case you are not alone, take turns capturing quite than it turning right into a “free for all.” You’ll all get higher photographs this fashion. Bear in mind to not damage others’ photographs if you’re not capturing: Don’t swim beneath them, making a cloud of bubbles; keep out of their backgrounds; and don’t shine your mild onto the themes or into their lens.


Digital camera Tools and Settings

Provided that an encounter with a blanket octopus is something however assured, organising in a devoted wide-angle configuration, particularly to shoot a topic their dimension, would imply lacking out on many different blackwater photograph alternatives, given that almost all different topics require a macro setup.

The go-to lens for blackwater is a 50mm/60mm macro lens that focuses shut and quick, giving a 1:1 (or close to to) copy ratio. Longer lenses within the 100mm/105mm vary are usable however will make your life tougher. Up till not too long ago, attributable to autofocus efficiency and appropriate lenses, the most well-liked blackwater setup was a Nikon D850 or Nikon D500 mixed with the Nikon 60mm macro lens, although with the latest launch of the Nikon Z8, Sony a7R Mark V, and the forthcoming Canon EOS R5 Mark II, your choices are definitely not restricted to Nikon DSLRs anymore.


A small feminine blanket octopus, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


In case you are capturing a full-frame digital camera, one can find that the 60mm lens will adequately accommodate the proportions of all however the largest people. However I discovered that capturing Nikon DX (ASP-C) format, with the 1.5 crop issue, it is advisable to again off a bit of too far to suit the topic within the body. And extra distance equals extra backscatter.

That is the place the Kraken KRL-09S wide-angle conversion lens comes into play. (The Nauticam MWL-1 does the identical job, simply at greater than double the worth.) I’ve this mounted onto my D500 (for blackwater, I choose the D500’s DX sensor and speedy AF over the D850) on a flip adapter, so if the event arises to shoot one thing larger, it’s a merely a matter of flipping the lens down into place after which shortly adjusting strobe place for the broader body. This lens offers you 154° area of view when mixed with a 60mm on an FX (full-frame) sensor, so is much less on DX, however it’s excellent for a topic the dimensions of a blanket octopus. You will get a lot nearer, reducing down the water column between the lens and topic for vastly lowered backscatter and sharper, extra colourful photos.  

Lighting may be achieved from any good-quality strobe, with delicate, even lighting being optimum, so use diffusers to assist scale back mirrored highlights. A quick recycle time is useful for quick capturing, permitting you to seize extra accurately uncovered frames briefly moments of motion. You don’t need to be lacking the shot because the blanket unfurls attributable to your flash not recycling shortly sufficient! I take advantage of Retra Professional X with the added Supercharger battery packs to halve my recycle instances, plus the delicate diffusers. An LED flash set off, or digital sync cords, are a greater possibility than capturing with the digital camera’s pop-up flash, because the on-board flash has a slower recycle time, which is able to then turn out to be the deciding issue on capturing velocity. You may usually lower the ability of the on-board flash to hurry issues up if that is your solely possibility.


{A partially} unfurled feminine blanket octopus, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


Blanket on full show, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


The most effective autofocus mode will rely in your particular digital camera. For blackwater capturing with my D500, I completely use the Steady-Servo 3D Monitoring mode. I’ve discovered this greatest for monitoring the smaller critters, whereas on the similar time not being detrimental for bigger topics the place one other AF mode might carry out higher. I don’t need to be losing time adjusting pointless digital camera settings when a blanket turns up; I must react shortly, getting right into a capturing place whereas concurrently transferring the strobes wider and flipping the moist lens into place.



The stand-out characteristic of a feminine blanket octopus is understandably the colourful membrane possessed between its arms; they’ll simply be mistaken for a extra widespread species if the blanket just isn’t seen. Don’t chorus from capturing when the blanket is retracted although, as they’re nonetheless photogenic, however a shot with the “blanket” on show is the final word objective.

If the blanket is lacking, it’s the equal of your catwalk supermodel whipping off her Versace costume and revealing a Primark tracksuit beneath—she’s nonetheless fairly however appeared loads higher within the designer outfit! Nevertheless, even in case you are fortunate sufficient to come across this beautiful cephalopod, there isn’t a assure that she’s going to unfurl the blanket. If she does, it’s going to fairly in all probability be for a short second, so along with being fortunate, you’ll should be on the ball if it occurs, to make sure you are in the correct place to seize the shot.


The cool, however a lot much less “horny” of the blanket octopus genders, the male, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, f/25, 1/250s, ISO400)


A side-on capturing angle is what I’m aiming for almost all of the time, as this exhibits the form of the octopus, offers sturdy eye contact and, if the blanket is unfurled, this can turn out to be the middle of curiosity. Partially angled photographs additionally work properly, as this could nonetheless present the colourful blanket whereas sustaining good eye contact. A head-on shot isn’t as efficient for me, although can nonetheless present form and shade, however doesn’t usually have sturdy eye contact, resulting in a weaker composition. In case you are additional fortunate, whereby you encounter one at or close to the floor, it’s best to try to include floor ripples and texture into the composition, making a extra attention-grabbing background than plain black. You probably have calm sufficient floor situations, look to seize reflections by capturing at a barely upward angle (however not too steep) to the floor.


A feminine blanket octopus poses in entrance of a diver, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


In April this 12 months, while staying at Crystal Blue Resort in Anilao with Mike Bartick, we have been handled to a sizzling week, giving us encounters with blanket octopuses on three separate dives. The ultimate encounter was temporary and chaotic, giving us a minute of mayhem when 4 blanket octopuses confirmed up on the similar time! Our information, Jhomel, noticed them swimming down from the floor and frantically signaled Mike and me over.

Mike was a fraction forward of me and went to at least one on the left, so I went proper. However that they had our quantity, and with each of our eyes glued to the viewfinder taking away our peripheral imaginative and prescient, they comically guided us each into one another, then sped away. I solely managed two frames earlier than they have been gone, leaving me blowing huge clouds of bubbles after a 100-meter dash at 32 meters! Upon checking my photographs after the dive, I had nearly managed to seize a body with a second blanket seen within the background. Granted, it’s not one of the best shot, but it surely’s an excellent memento of a really cool, albeit temporary, encounter. It was the primary time Mike had seen grownup females collectively.


A duo of feminine blanket octopuses holding their namesake “blankets” hidden, Anilao, Philippines (Nikon D500, Nikon 60mm f/2.8 macro, Kraken KRL-09S, f/32, 1/250s, ISO400)


The dive season in Anilao runs from November by to June, although peak season is from January to April. Blanket octopuses are encountered at any time of 12 months, although this previous April was significantly good, with a number of sightings over subsequent days. If you want to affix Mike and Alex subsequent 12 months at Crystal Blue Resort in Anilao, they’ve a particular “Blackwater Week” deliberate for April 2nd–ninth, the place they are going to full critter dives through the daytime after which two blackwater dives each night time. If you want additional data or are thinking about becoming a member of, please contact Alex at [email protected] for extra data.

Alex Tyrrell is an expert underwater photographer and underwater pictures teacher primarily based on Koh Tao, Thailand. His firm Dive4Photos teaches all ranges of image-makers methods to enhance their diving and photograph expertise. To see extra of Alex’s huge portfolio of photos, try his web site,