Chardonnay may be okay but beware the Pinot Grigio
By Peter Swanson
In his Master and Commander series, author Patrick O’Brien describes one far-off ocean as a “wine-dark sea.” O’Brien could have been describing the Tongue of the Ocean in the Bahamas where a boat can navigate with a comfortable 6,000 feet beneath the keel. In the other extreme, if Bahamian water looks like Pinot Grigio, back down on the throttles because your boat’s about to run aground.
Those are the extremes of “eyeball navigation” in the Bahamas; dark blue water means very deep and yellowish-white signifies the skinniest of waters. The skill, which comes with experience, is deciphering the blue-green gradations in between. For that 5 percent of the male population that suffers from color blindness, Bahamian cruising is no doubt angst-filled, requiring extreme conservatism and reliance on the observations of others.
That’s because neither paper charts nor electronics substitute for the human eye when navigating the shifting sands of the Bahamas’ shallow banks and inlets. Depth sounders can only tell you the depth at that moment, not which way to turn to remain in safe soundings. Navigational markers are virtually non-existent.
That having been said, learning to associate colors with depth doesn’t take years of Bahamian cruising experience, or even months. As mentioned, deep blue means deep water. As the blue lightens it means the sun is reflecting off a rising bottom. Green begins to dominate as the depth shallows to 40 feet. That postcard perfect green-blue signifies a navigable 6 to 9 feet of depth. Yellow or white: don’t go there.
Among the most dangerous hazards are keel-ripping coral heads, which appear as black patches against the green water. Insidiously, some coral heads rise to just a few feet below the surface of what is otherwise deep water. In this situation, the prudent thing to do is avoid any dark spots. To further complicate decision-making, grassy spots also show as dark brown or black. Best avoid them all, as one cruising guide author once wrote, comparing them to mouse droppings in the pudding.
Clouds, too, are your enemy because not only do they obscure bottom colors with their shadow, but the shadow itself can be confused with dark coral heads. Best remember, however, that coral heads stay put.
Color differentiation is key, of course, and that ability can be enhanced by three factors: polarization, timing and elevation.
Buy yourself some good polarized sunglasses. If you never have, you’ll be amazed how much more vibrant the colors will seem. Shadows and gradations in water color that can easily be missed with ordinary sunglasses become more defined.
Late risers have the edge in Bahamian cruising because the low morning sun doesn’t sufficiently illuminate the bottom to bring out the colors, particularly if the sun is ahead of you. Eyeball navigation works best when the sun is high and behind. If depth is a factor at your destination, this dictates a rather short cruising day, say from 10 a.m. to 2:30 p.m., with plenty of daylight left to swim or hunt lobster. Obviously, night cruising on the banks is risky at best.
Another way to give your eyes an edge is to elevate them, particularly if waters are choppy. Sportfish towers and flying bridges, of course, are ideal for this. Standing on the cabin top with an autopilot remote is almost as good. Lacking that, communicate. Some trawler cruisers have wireless headsets for docking; these can be handy as one partner, high up, calls out directional changes to the other at the helm. Otherwise, you’ll just have to do it the old-fashioned way—by hollering at one another.