Ice is often said to be suitable for foot travel when it becomes approximately 4” thick. Of course, caution must still be taken because ice seldom, if ever, develops uniformly. There are simply too many influencing variables–including the elevation, shape, type and depth of the waterway, the presence, direction and strength of wind or currents, springs, emergent objects
—even the presence of waterfowl can effect ice formation. Most modern ice anglers have familiarized themselves with these factors, and rightly so.
But this somewhat peculiar El Nino winter of 2015-16 sheds light on two other less recognized, yet equally critical aspects of ice development often remaining overlooked: Composition and tensile strength. While somewhat less understood, these two characteristics are no less relevant to ice safety than the more commonly realized elements mentioned above. For the sake of example, let’s consider two extremes.
The advance of a severe arctic cold blast settling over a calm, open water surface, suddenly plummeting temperatures into single digits or below zero (Fahrenheit), will produce a clear, strong, solid layer of what’s often referred to as “blue” ice—a stable, firm, quality foundation capable of supporting a significant amount of weight for its depth. Four inches of ice in this condition is enough to convince me the lake is accessible.
In contrast, let’s say the same lake, still unfrozen, is suddenly struck by the advance of a strong winter storm featuring heavy, wet snow falling at a fast rate—fast enough that an accumulation of slush settles across its surface, followed immediately by temperatures just cold enough to allow this collected, floating mass to freeze. The result? An inconsistently formed, unstable layer of “white” ice filled with air pockets, offering weak cohesive bonding and very little tensile strength.
This brittle coating is incapable of supporting any significant weight. Four inches of ice in this condition is certainly NOT conducive to fishing—in fact, I’ve heard stories of ice anglers encountering pockets of white ice three, even four times that thick experiencing undesirable results.
The lesson? Be cautious. Take time to truly understand the myriad of variables involved with both ice formation and condition. After all, no fish is worth a life.
And remember, as the concerned sergeant on the popular 1980’s TV show Hill Street Blues always soberly stated at the conclusion of every staff briefing: “HEY, LET’S BE CAREFUL OUT THERE!!”