Thursday, February 21, 2013

The Box Canyon Rule

Zebulon, North Carolina

The most valuable and lasting benefit I got from learning to fly airplanes is what I call "The Box Canyon Rule."

Here's the problem.  Every year several people lose their lives trying to fly airplanes up box canyons in the American West.  It must be very tempting.  The problem is, what do you do when you get  to the dead end? Well, plan A must be to either climb out of the canyon, or to make a U-turn and fly back out again.  In real life, that does not always work; and when it doesn't lives are are snuffed out on the canyon walls.   The significance of the box canyon is that there is no feasible plan B.
The box canyon rule is simply, "Don't fly into a box canyon."
The more general form of the rule is, "Don't follow any plan to which there are no feasible alternative plans."  
The risks I try to avoid while cruising are more abstract than real box canyons.  Here is a (non-exhaustive) list of factors.
  • The obvious ones.  Do not sail into uncharted waters (i.e. waters I don't have charts for.)  Do not enter strange harbors at night.  Don't go where currents are too strong to overcome with our vessel.
  • Weather margins.  I always try to return to a safe port at least 24 hours before an acceptable weather window may close.  If dangerous weather approaches, my margin increases to 36 or 48 hours.
  • Navigation: If all 4 GPS apparatuses on board suddenly fail, I have ways to do backup navigation.   I also have multiple backups for engine failure, sail failure, and hull integrity failure.  We have ample food and water to keep going for many weeks.  We have multiple methods of backup communication.
  • Personal limits:  I never allow our reserves of endurance or good judgement get dangerously low.  I'm keenly aware that fatigue robs judgement, and that as we get older fatigue appears quicker and that we fatigue more rapidly in bad weather.
Don't assume anything if you can avoid it.  To avoid collisions we keep a safe distance from other boats when possible to avoid the need to assume that the other guy will do the safe thing.  We always talk to a draw bridge tender by radio rather than assume that he sees us.
Here's the method: Think critically about your assumptions.  If an assumption is critical to safety, then you must have a feasible backup plan if that assumption proves false.  If you don't have a feasible alternative, don't go.

I should also define safety in this context.   Of course life safety is foremost, but for me that's not safe enough.  I plan to avoid situations which could be so scary, dangerous, or financially ruinous that it would cause Libby and I to give up on our cruising life.   We have no backup for this life style choice.  We must make it work.

In part, that is the reason for our current stand down.  I sensed that we (the crew) and Tarwathie (the vessel) were becoming accident prone.  Our implied plan A was that no such accident would be really serious.   Once I recognized that we had entered a box canyon, I chose to back out immediately.  I hope to make both the crew and the vessel in better shape to resume cruising next year.

[Note: I first posted this item on 11/8/2010, then I immediately withdrew it for rewriting.  This is the improved version.  Jim M,  read the first version before I withdrew it.  His comment was: 
Dick --
Your Box Canyon post is superb and should be required reading for all boaters. It is the most clear and articulate writing that I have seen on why and how to think about risk in a boating environment but is very broadly applicable no matter the boating style.
BTW, professionally, I am a risk manager as I run the credit function for financing large scale energy projects so I really appreciated the post both personally and professionally. Jim M. in CT 


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