Hatteras, NC (September 2022)
diving aboard Lion's Paw
Shipwrecks FW Abrams, Proteus and Dixie Arrow
Boiler Tube Creatures
So many of the shipwrecks we explore are old steamships, powered by coal-fire boilers producing steam for the reciprocating engines. The majority of these boilers are massive steel or iron cylinders that endure the marine environment for a long, long time. The lower half of a cylindrical boiler usually contained between two and four furnaces, where coal-stoked fires burned to heat water inside the boiler and change it into steam. It was soon discovered that additional heat energy could be drawn from the hot furnace gases that were a by-product of the coal fires. This was accomplished by venting the hot gas through a series of small tubes that passed back through the boiler before being exhausted out the familiar ship's smoke stack. These tubes can usually be seen on the flat ends of a cylindrical boiler, about midway up the face and above the large cylindrical furnace openings. It is these "fire tubes," as they are sometimes called, that today provide a fascinating marine habitat on many old steamships. Forming a honeycomb-like structure much like a beehive, these banks of boiler tubes amount to an underwater apartment complex for a wide variety of fish and invertebrate life. Measuring two to four inches in diameter, each tube is the perfect size for a small animal or fish. In many ways they are reminiscent of the apartment-like bird houses sometimes erected for purple martins, with each individual boiler tube serving as a home for a tiny, individual animal. I first noticed this wonderful adaptation of an old boiler off the coast of North Carolina many years ago, and since then I check out these little critters on a regular basis. On our most recent weekend in Cape Hatteras, with the visibility a bit on the murky side, I spent all my dives shooting these little critters. . .
|Sharks swim over the Proteus' boilers (right and left); a matrix of fire tubes punctuate the boiler's flat end, providing a myriad of homes for small critters (center)|
|blenny and small red fish (left); crab and pencil urchin (right)|