An oil tanker was bearing down on us, the concrete pilings of the Sunshine Skyway Bridge were fast approaching, and the pilot of our ship had his head covered with a blinder and his eyes riveted on a small electronic screen.
The making of a maritime disaster? No, it was a test of a new navigating device that may help avoid a calamity.
Working with Greiner Engineering Sciences Inc. and Navigation Sciences Inc., the Florida Department of Transportation (DOT) has come up with a new way for ship pilots to see where they are going.
Their work was initiated after an accident in 1980 in which a phosphate freighter rammed a pier of the Sunshine Skyway Bridge, which spans Tampa Bay near St. Petersburg. A portion of the bridge collapsed, killing 35 people. The collision occurred in a rainstorm so intense that it not only hid the bridge from the freighter pilot's sight, but also distorted his radar so he could not locate the bridge electronically.
The device the DOT is testing works by improving on the Coast Guard's Loran-C navigation system, which uses radio signals to tell mariners where they are. The Loran system does not work well in harbors or bays because the radio signals are distorted by the land.
Navigation Sciences developed a land-based microwave system that constantly measures the distortion and feeds figures into an onship computer, which then compensates for it.
''This is the only one like it in the world,'' said Mortimer Rogoff, president of Navigation Sciences. ''It relies on new ways of using Loran that gets accuracy 10 times better than a normal Loran.''
One of the devices was put aboard the Coast Guard buoy tender White Sumac, and Tampa Bay pilot Gary Maddox was asked to guide the ship under the Skyway while wearing a blinder so he could not see where the ship was going.
Instead of looking out the windows at the buoys and range finders, Maddox was watching the progress of the ship on a screen attached to a computer and guided by radio signals.
On the screen was a chart of the shipping channel and the markers that align it. The location of the ship was pinpointed on the chart, and as the ship moved, its path was followed by a line.
Numbers on the screen told the pilot how far he was from the center of the channel, how far he was from the next obstruction - be it a turn in the channel or a bridge - and how long it would take to get to it at the ship's rate of speed.
Looking at nothing but the screen and giving instructions to the helmsman, Maddox guided the buoy tender down the channel, around two turns, executed an evasive action to avoid an oncoming tanker, and traveled under the Skyway in the center of the channel.
''Our worst fear is the summertime thunderstorms that block our vision and distort the radar, and this machine has the capability of telling you where you are within five meters,'' Maddox said. ''This machine would have given (the pilot aboard the ship that hit the Skyway) the capability to know he was off course early on.''
If the Tampa Bay pilots decide after six months of tests that they have confidence in the new system, the DOT will ask companies to bid on making several systems that would be light enough for pilots to carry aboard all vessels.