In "Thunder on the Blaauwberg", by Lawrence G. Green, chapter 24 is titled "The Kraken Sleepeth". In it a story is told of a fishermen who, while wading over shallow rocks in Smitswinkel Bay, near Cape Point, noticed something resembling kelp in the water, but which turned out to be a giant octopus. The octopus reached out and managed to grab the fisherman by his leg. Using a knife he managed to cut the tentacle off, but a second one reached out and grabbed him by the arm. Again, the knife helped him out, and he managed to free himself and escape. During this ordeal the fisherman estimated the length of the tentacle to be "nine or ten feet long" (nearly 3 meters!), and managed to retrieve the tentacle cut off and measured that "the circumference was nine and a half inches, and this was near the tip." So, tentacles nearly 3 meters long, with a circumference of 24 cm, giving it a diameter of 7.7 cm, near the tip. This certainly was a big animal.
The question is, is this just another fishermen's tale? Or could this have been real, and if so, where are such octopus now? First of all, the author of the book is well aware of the difference between an octopus and a squid, and mentions large squid washed on-shore - these were referred to as "kraken" in old shipping stories, hence the name of the chapter. But does an octopus exist which can measure up? Yes, there is, the giant Pacific octopus Enterctopus dofleini can grow arms to at least 2 meters, with a body of 60 cm, which is certainly close enough to the octopus described by the fisherman. It however only occurs in temperate northern Pacific waters. A similar species, Southern giant octopus Enteroctopus magnificus (probably misnamed as Octopus dofleini in "Oceans of Life"), does occur in our waters, from Namibia to Port Elizabeth. While "Oceans of Life" gives a total length of 3 meters, "Cephalopods, a world guide" only mentions a body length of 35 cm, with arms to at least 1.5 meters. This is about 1 meters short of that described by the fisherman, although it is quite possible that the length was over-estimated. The species according to "Oceans of Life" is taken by trawlers in 200m deep waters, but it is described in "Cephalopods, a world guide", as ocurring from shallow subtidal areas down to 1000m deep. It is thus highly likely that the fisherman encountered this species.
The next question is, if they occur, why do divers not see them? This is not something one can answer with ease. SURG members believe that they have seen one at Vulcan Rock once - the overall appearance of the giant octopus is different from the common octopus Octopus vulgaris, in that, apart from being larger, it has a mostly dark red, spiky appearance, but are not quite certain it was identified correctly. But, where are the others? An octopus this large is probably not common to begin with, and "Cephalopods, a world guide", mentions that the harvest of this octopus is small, and then mainly as a bycatch in trawl fisheries, or occasionally in lobster pots. Add to this that the preferred habitat seems to be sand and mud areas, where divers only infrequently go. It is thus possible that the octopus occurs more frequently than we think, we just never encounter it! As to the fisherman - he probably just had a rare and unusual encounter!
Thunder on the Blaauwberg, LG Green, 1966
Oceans of life of Southern Africa, AIL Payne, RJM Crawford and AP van Dalsen, 1989
Cephalopods, a world guide, M Norman, 2000