Underwater Photo of the Week

Hi Gang!

This week’s POTW is an image of a sandbar shark that I captured in Hawaii on a dive with Captain Steve. On this dive we were over on the Northshore of Oahu diving with legendary shark expedition leader Jimmy Hall. I have also seen sandbar sharks off Maui and the Big Island as well as on some shipwrecks off North Carolina.  Even though the dive takes place more than three miles off the coast and over a very deep bottom, it is usually run as a cage dive with the divers using surface supplied air via a hookah set up. The feature attraction is the almost always present gathering of Galapagos sharks. The sandbars are seen on a regular basis, but they are not usually as numerous as the Galapagos sharks.

On this day we had somewhere in the neighborhood of 30 Galapagos sharks and a half-dozen sandbar sharks swimming in the clear blue water around the cage. Unfortunately, the weather and water conditions were less than favorable, but Jimmy had told us that we could bring scuba gear and get out of the cage if we wanted to. With the waves and swell causing the cage to bounce around quite a bit we decided to get out of the cage to see if we might be able to get a little closer to the sharks and hold our cameras a little more steady while we captured our images. Not easy to do in a bouncing shark cage!

The way I tell the story I was the first to venture out of the cage to see how the sharks would react and how close I could get while Steve watched from inside of the cage. But in Captain Steve’s version of the story he went first and had to pull me out kicking and screaming a few minutes later. Since this is my column, let’s go with my version.

Actually neither one of us was smart enough to remain inside of the cage, but being on the outside did provide us with some great photographic opportunities.

The sandbar shark (aka brown shark, queriman shark and thickskin shark) is an impressive looking, medium-sized shark that reaches a maximum size of just over 6 feet and 260 pounds. The tall dorsal is a good identifying feature. So is the fact that, at least in my experience, sandbar sharks appear to be a bit on the nervous side as they rush in from a distance, take a close look and then give ground or disappear. Often they appear again within seconds.

Sandbar sharks occur in subtropical and tropical seas around the world in both inshore and offshore waters. They are common in river mouths, bays, estuaries and harbors, but tend to stay away from surf zones and beach areas. While the sharks we saw were very close to the surface, sandbar sharks are documented to visit deep waters, especially when they undergo migrations.

Sandbar sharks are opportunistic feeders that prey upon a variety of bony fishes, smaller sharks, rays, mollusks and crustaceans. While actively hunting during daylight hours, sandbar sharks are believed to be even more active under the cover of darkness.

Taking a relatively long time to reach sexual maturity and with a low reproductive rate, the species is especially vulnerable to being over fished.

I enjoy sharing this image. It reminds me of a great diving day in Oahu with Captain Steve, Jimmy Hall and some other friends. Unfortunately, Jimmy passed away while base jumping on Baffin Island in the Canadian Arctic not too long after our dive. I am glad I got to know him and dive with him. He certainly was a lover of sharks, and his enthusiasm for sharks and adventure was contagious. His wife continues to run the shark trips.

I captured this week’s POTW image with a Nikon 17-to-55 mm zoom lens, an excellent lens for medium-sized sharks and other similarly sized animals such as sea lions and eagle rays. The zoom capability of the lens enables me to fill the frame even when I can’t be right on top of my subject. I want to be careful not to be too far away because the image will “fall apart” if I try to shoot through too much water, but if used well, this lens is a great tool for photographing many species of sharks.

With my Subal housing and wide-angle port, I use a plus 2 diopter with this lens. I used a pair of Ikelite DS 125s to light the shark.

Hope you enjoy this week’s POTW!

See you next week!

Marty