Professional Association of Diving Instructors
- On 19/08/2011
- In Wreck Diving
By Kelly Nicholaides - North Jersey
Early maritime navigation challenges, weather conditions and greedy shippers pocketing insurance money have led to over 5,000 shipwrecks in New Jersey, according to Chet Nesley, a Professional Association of Diving Instructors master instructor.
Nesley, who has logged over 4,000 dives in water ranging from 20-160 feet deep for shipwrecks, discussed maritime and shipwreck history, complete with a PowerPoint slideshow presentation, color photos and artifacts at the Meadowlands Environment Center in June.
"A shipwreck never gives up all its booty. There's always something to find," Nesley notes.
In maritime history, navigation tools and a seaworthy vessel were keys to preventing shipwrecks. A wooden ship depended on the wooden rods that held them together before nails existed.
"The wood swelled up in water, making it a tight fit. Sawdust filled in the spaces in between, so you had a watertight ship. The worst thing for a wooden ship is keeping it dry," Nesley says.
One such rod, a "treenail," is among Nesley's treasure troves from his shipwreck dives. But preserving the items is just as difficult as finding them.
"If you're not going to preserve it, don't bring it up," Nesley notes. "I had to soak this in freshwater for six months. I stuck it in my toilet tank."
How and why vessels had sunk is equally important as a ship's artifacts, he explains. "The challenges of early shippers was they had no GPS, no radar, no radio.
The best charts were made by the British navy, who surveyed harbors and charted landmarks, all by hand. You had to have a good handle on math, trigonometry and algebra," Nesley says.
Getting lost was not uncommon.
"But as long as you could see the moon, the sun or the North Star, you had an idea where you were," Nesley explains.
Navigation was tricky. Vessels that got lost in a fog or made complex navigational errors include warships, passenger liners, freight, fishing and clamming boats. Even if shippers knew the latitude, longitude was not easy to find.
"You needed the time at prime meridian and local time," Nesley says.
"Dead reckoning" used the course, speed and time to figure out the position.