Coming face to face with wild animals in their natural habitat and observing their behaviours has an almost universal appeal. It's why we have such a soft spot for the likes of David Attenborough and Steve Backshaw (ask the children). But while the animal kingdom above the waves is home to spectacular and bizarre behaviours, the aquatic kingdom is positively alien. So whether you're a diver with thousands of hours under your dive belt, or an absolute beginner, these are the amazing marine life behavioural moments that you'll never forget…
Manta Feeding Frenzies, Hanifaru Bay
There are several destinations where manta sightings are both reliable and outstanding, but there is one that stands alone above the rest. Between the months of June and November, Hanifaru Bay in the Baa Atoll in the Maldives plays host to the most spectacular conglomeration of mantas, all there to feed on the massive plankton bloom. If you've ever wondered what it would be like to dive inside a swirling vortex of manta rays, you'll find your answer here, as hundreds of them flip and fly all around you in a feeding frenzy. Even better, this amazing marine life spectacle can be viewed from the surface so snorkellers can also apply.
Sardine Run, Mexico
Made famous by the BBC's Blue Planet for its insane cast of predators both above and below the waves, the Sardine Run off the coast of South Africa has become a hot spot on every diver's bucket list. Lesser known, but equally - if not more impressive - is the bait ball that collects off the west coast of Mexico. A last-ditch defensive measure adopted by small schooling fish when they are threatened by predators, bait balls see huge shoals of sardines and mackerel amass in Baja California's Magdalena Bay attracting the striped marlin migration, there to feast on the yearly bait balls. Sea lions, dolphins, sharks and whales all join the party, as the water is churned up by their feeding frenzy. As they chase the fish toward the surface, bald eagles and other seabirds swoop down for their share in the feast. You won't know which way to look as this epic dance of life and death plays out all around you.
Foraging Underwater Iguanas, Galapagos Islands
One of the most iconic creatures in the Galapagos islands has to be the marine iguana. Developing the ability to forage for vegetation in the sea set this reptile apart from its continental cousins, in the process helping Charles Darwin formulate his theory of evolution. The Galapagos Islands are home to unique (in the true sense of the word) wildlife and the nutrient rich waters surrounding the islands - where ocean currents collide - result in an explosion of life (20% of which is only found here). Though Darwin described them as 'hideous looking' and the 'most disgusting, clumsy lizard,' we believe these guys have their own charm and are actually quite elegant and at home in the water. Conditions tend to be quite rough, with strong surge and breaking surf so spending quality time with these 'clumsy lizards' is an experience for experienced divers only.
Schooling Hammerheads, Galapagos Islands
While we're in the Galapagos, the schooling hammerheads cannot be missed. Scientists are still puzzling as to why hammerheads congregate in their thousands when most sharks prefer a solitary life, but the dominant hypothesis is that it has something to do with their migratory and breeding habits. Whatever the reason, it's a surreal moment when you look up towards the surface to see hundreds of hammerheads silhouetted against the surface. The islands of Cocos, in Costa Rica, and Socorro, in Mexico, are also phenomenal destinations to spot this once in a lifetime event.
Extreme Bioluminescence, Turks & Caicos
If you've ever done a night dive, chances are at some point you shut off your torch, agitated the water and saw it illuminate in fleeting specks. The first time you do this as a new diver, it almost feels like magic, but the more time you spend underwater the more you realise the creatures there live by a completely different set of rules. The phenomenon that occurs in the shallow waters of the Caicos Banks in the Turks and Caicos Islands occurs for several nights following the full moon and is produced by the reproductive dance of a glow worm. Every month, and just after sunset, the female glow worms release their egg sacks which glow bright green and float to the surface. The males, also illuminated, dance their way up to fertilise the egg sac, making them glow even brighter, before sinking to the bottom to die. It's a short and astounding life cycle, which results in one of the most spectacular spectacles where the entire surface appears to be glowing.