Matador Community member William Goodwin recalls his time spent at Aquarius.

IN THE BACK OF MY MIND, I was aware of the dark line of the Upper Keys barely visible on the horizon as I concentrated on the tender’s voice going through the check list.

Air on? Check. Regulator functional? Check. Touch it! Check. Cutting tool present? Check. Touch it! Check.

When all was ready, I took a step and jumped off the back of the National Oceanic and Atmospheric Administration (NOAA) work boat and swam directly down 50 feet to Aquarius.

I was fortunate enough to make six dives to Aquarius during the first mission of 2011 as a guest of Joe Pawlik, the scientist heading the sponge research.

On my first evening at the researchers’ dorm — a shore-based facility on the seaward side of Key Largo — I got a taste of how unusual this was going to be. Joe and I were chatting when his phone rang. He glanced at the screen. “Oh, Aquarius calling. Gotta take this…”

He talked about a few technical matters before adding, “Guys, I just had the best watermelon — it was so good that I bought one to bring down to you. Watermelon at the bottom of the ocean, anyone?”

[Note: Matador editors selected this Community blog post for publication at the Network.]

1

Aquarius

Aquarius appeared larger than I expected. Here, a diver is about to enter the "wet porch," where he will kneel on a grate in waist-deep water that allows him to lift his head and chest out of the water and into the humid air of the habitat. Once outside of this "moon pool," a hot shower helps to remove the salt water before drying off and entering the habitat.

2

Outside Aquarius

Fish and sessile sea life crowd the outer surfaces of Aquarius. The space at the lower right corner is the entrance to the wet porch. Unseen below that is a 10-foot high open-sided "basement" filled with fish.

3

The moon pool

Looking into the wet porch (occupied as usual by a squadron of grunts and snappers) reveals the mirrored underside of the "moon pool" -- the interface between the sea and the air inside the habitat. Aquanauts inside the structure have hung their scuba gear on the underwater rack.

4

Hope you don't snore

The climate inside Aquarius is controlled, comfortable, odorless, and dry. Six aquanauts sleep in these bunks wedged into the forward section of the habitat. Carbon dioxide scrubbers are located under the lower bunks.

5

Goliath grouper

Crowds of small fish stay out of the way of this immense Goliath grouper. This one is at least two decades old and has lived at Aquarius for much of its life. It trailed a long line from a hook in its mouth.

6

Under the feet of aquanauts

The pressurized air in Aquarius is twice as dense as on the surface, and when I speak, my voice is noticeably deeper. But not as deep as another sound frequently heard inside the habitat: the "booming" of these two hefty Goliath groupers that live literally under our feet. After dark, the larger one often peeks inside to people-watch through one of the ports.

7

Giant Barrel Sponges

The quantity and variety of sponges growing on Aquarius is astounding and mesmerizing. So far though, none of the Giant Barrel sponges found on the surrounding reefs have taken up residence on the habitat walls. I'm told those guys filter enough water in a week to fill an Olympic-sized swimming pool.

8

Watermelon at the bottom of the ocean

Because the aquanauts cannot return directly to the surface without a lengthy decompression procedure, shore-based assistants act as couriers between the surface and the habitat. Here, a diver delivering a watermelon to the aquanauts hears a cracking sound coming from within the melon. Gladly, the aquanauts found the rind intact and the fruit inside conveniently broken up for them.

9

Webcasting from the ocean floor

Most of the time, divers use scuba to explore the reefs. Sometimes, however, they connect to an umbilical with air delivery and electronic connections that allow live webcasts from the camera mounted on the diver's lightweight helmet.

10

Instruments and recording devices

Here, a variety of water- and pressure-proof measuring and recording devices are attached to a cluster of sponges. These are placed and attended to by aquanaut scientists working with Dr. Joe Pawlik from the University of North Carolina, Wilmington.

11

Dog Snappers in the basement

Beneath the habitat, the local sea life seems content to loiter, socialize, mate, and eat in the shadowy "basement." Here, a pair of large Dog Snappers are building up to spawning at dusk. The "tear streak" is characteristic of this coveted-by-fishermen species.

12

The "wet porch" grate

The pressure in Aquarius is kept slightly above the ambient water pressure to prevent the moon pool from flooding the habitat. Here, an aquanaut partially emerges from the moon pool on the "wet porch" to discuss a matter with a technician inside the habitat. It's extremely humid here, as befits a space that's open to the sea at 10 fathoms deep.

13

Blue Striped Grunt hunting for snacks

This self-conscious Blue Striped Grunt looks for edible tidbits amongst the sponges on one of the habitat's support legs. Aquarius doubles as a marvelous artificial reef, which attracts many kinds of fish. The area is marked off as a preserve, and fishing and sport diving are prohibited.

14

Queen Angelfish

One of the brightest colored fish on the reef, this Queen Angelfish grazes on a sponge growing from the Aquarius structure. Sponges comprise a large part of the diet of most angelfish, yet the habitat's prolific population of sessile creatures somehow stays ahead of the considerable feeding pressure from the large number of fish.