The Seaman’s Eye Fallacy is the belief that using better tools to measure what can be judged by eye is not seaman-like.
When I wrote on a post that the lack of a working anemometer would be an issue for a ship approaching a hurricane at night I never expected any disagreement. Seems like a no-brainer. It’s a matter of making reliable, consistent and accurate measurements. To measure is to know.
However when the question about using rangefinders was brought up, I fell into the same trap. My first thought was what kind of seaman needs a rangefinder to know where his ship is when in close proximity to piers? What kind of seaman would fess up to the lack of a seaman’s eye? Worried that he’s lost, twenty meters off the pier? Or is it forty? Who can tell, no way of knowing!
However after I gave it a little more thought I recalled “to measure is to know” and decided it was simply a matter of a cost benefit calculation and convenience. If having rangefinders is worth the cost by lowering risk or increasing ease then they should be used.
However not everyone agrees. So, why is it that the idea of using instruments to measure what can be estimated by eye strike some as poor seamanship?
It’s because of the pride mariners take in having a “seaman’s eye. Judging how your ship is moving and knowing where your ship is in relationship to the pier or other ships, judging wind speed and direction are the essence of the seaman’s eye. Mariners that have developed these skills are proud of these hard won skills and are what separate the skilled seaman from the rest.
But there is pride and there is hubris.
“He was conning the ship by [B]seaman’s eye[/B]?” asked the Coast Guard veteran of 24 years. “That’s negligence.”
[B]Seaman’s eye is a term for the art of “visual navigation,” using ranges, angles, various objects and water color, aided by compass, depth sounder and other devices.[/B] We all use [B]elements of seaman’s eye [/B]every time we head out. And Dein is a strong believer in the method on smaller vessels and when circumstances warrant it. But on a cruise ship nearly the size of an aircraft carrier that is pressing questionably close to shore? “You would never do that except in dire emergencies,” Dein says. “It’s too big a risk. It’s a hell of a risk.”
Of course a seaman’s eye is going to add to the safety margin if used in conjunction with measuring tools and instruments. Some mariners will use these tools as a crutch and never develop a good eye, but others will use whatever aids are available to get more accurate information, not just to get the job done but also to adjust and calibrate their “seaman’s eye”