Seeing this massive school of Jacks was a total thrill, at a destination where every dive is pretty awesome. Schooling hammerhead sharks, marble rays, silvertip sharks, the white tip reef shark night dive rodeo at Manuelita Shallows dive site – Cocos Island still stands out as one of my most exciting dive trips ever.

This swarm of Jacks was so large and dense that when I ventured into the middle myself, they almost completely blocked out the light. The experience was disorienting, and magical.

In this part of Indonesia we were seeing some really unusual creatures and some beautiful reefs, but schooling fish were rare. I captured this image on a deep reef (about 90 feet) near Banda Island. This blended school of fish is comprised of Pyramid Butterflyfish and Longfin Bannerfish.

Hammer, hammer, hammer! Taken at Alycone Seamount — a fairly deep underwater mountain, this constellation of hammerhead sharks was pretty mind-blowing. Hammerhead sharks migrate to this area during certain seasons, and can be seen on most of the dive sites, but seeing them in a huge aggregation like this is pretty special.

Cozumel can be a fishy destination, especially on Paseo del Cedral, one of my favorite sites. Schools of grunts and porkfish appear to be regular residents on this site, and can sometimes be gathered in quite large schools.

Richelieu Rock ranks in my top ten favorite dive sites – and for good reason – there is great macro life, lots of varieties of schooling fish, and some divers are even treated to the occasional whale shark sighting here. Fusiliers are fish that are often seen in large schools, and they tend to move as one unit making them mesmerizing to watch.

I’ll admit it — catfish are weird critters, with their quivering whiskers and tight, wriggling school formations. These Striped Catfish can be seen on some of the shallow muck dives that are a highlight of the Indonesian diving experience.

This picturesque site is known as the Ambon Arch – due to its location just off the large island of Ambon in eastern Indonesia. When we dropped in on an early morning dive, we were fortunate to see this huge school of fusiliers swooping through the arch, and I got lucky with the shot. On a second dive later in the day, the fish were long gone…

Here we are back at Paseo del Cedral, this time to see a large school of yellow grunts, which seem to be omni-present on this site.

Lembeh, Indonesia, is a popular destination for muck diving hounds like myself, and it is only in this region of Indonesia that these beautiful Banggai Cardinal Fish can be seen. Although the schools tend to be small, and they tend to hover rather than swim, seeing a gathering of these gorgeous fish is pretty special.

Sweepers are small fish that are almost always seen in swarms like this. I’ve seen them in several locations, including Cozumel in the Caribbean, and in the Andaman Sea in Thailand and in Raja Ampat. This big beautiful school was photographed in Komodo National Park, Indonesia.

Fiji is another very fishy destination, and seeing large schools of snapper like this is not uncommon.

Muck diving in the infamous Ambon Harbor is all about the very weird and wonderful animals that live there, amongst the human-produced detritus littering the bottom. It is dirty diving at its best, and a macro photographer’s mecca. So it was with some surprise that I looked up into the murky water between me and the surface, and saw this very large school of little fish orbiting above.

As I mentioned in a previous caption, Fiji can be a very fishy destination. This image was captured in the Vatu-i-Ra passage (which runs between the large north and south islands of Fiji), and herds of fusiliers like these can be seen cascading over the reefs on several sites, most typically when current is present.

Here we are, back at Paseo del Cedral (did I mention how much I love this dive site?) These are schooling Porkfish, tucked under a colorful overhang.

Another early morning sighting, and a special one at that. Sometimes it pays off to be first in the water…

Not only is Fiji a fishy destination, but it is an extraordinarily colorful one too, thanks to the proliferation of soft corals that can be bright pink, purple, orange, yellow or white. Anthias are the little orange, pink and purple fish that gather on some sites — and they are fascinating to watch as they gather in the thousands — pulsing on the reef as they swim out to feed on plankton, then dive en masse into the reef at the slightest provocation from orbiting predators. This is very lively, and lovely, diving.

One more image, taken from a different perspective, to demonstrate just how massive (and dense!) this school of fish was. I’ve seen similar, but much smaller, schools of Jacks in Bali.

There are some pretty awesome things to be seen while diving — special creatures, great and and small, beautiful coral reefs, shipwrecks encrusted with life — but for me, one of the most heartwarming sights is a big, healthy school of fish.

I remember the first time I saw a swarm of fish — at Heron Island in Australia. Mr. G and I were relatively new divers, and it was our first trip to dive the tropical Pacific. There we were, bubbling along a pretty reef, when ahead of us we saw what literally looked like a dark cloud. As we swam closer, we could see that the cloud was actually thousands and thousands of small silvery fish, densely packed together. And even more amazing to us was how this huge whack of fish moved as one cohesive unit — quickly shifting left, then right, then up, then down, as numerous predators penetrated the pack to have their feast. At one point, the swarm of fish closed around us, and it was truly disorienting to be in the middle of the thing — and a bit disconcerting as well, as the predatory fish were torpedoing through on high speed passes as they ate their fill!

Since then we’ve been lucky to see schooling fish in several locations — including Costa Rica, Cozumel, Galapagos, Indonesia, Fiji and Thailand. I still feel that thrill when I see an aggregation of aquatic animals — and sad that this experience appears to be becoming increasingly rare, due no doubt to overfishing and loss of habitat.

If you are lucky enough to find yourself in the midst of a big swarm of fish, revel in the experience, but keep an eye on your depth gauge — it is very easy to become disoriented when you are completely surrounded by fish!

More from Judy G:

Meeting Mr. Big | Cozumel's Most Fascinating Creatures | Cold Water Rocks!