BOSTON –The Coast Guard is urging mariners to use caution as the combination of freezing water and air temperatures pose a serious threat to mariners.
As temperatures drop, the spray familiar to boaters can quickly turn to ice on equipment and the superstructure of a vessel, causing safety gear to malfunction and affect vessel stability.
In general, icing occurs when air temperatures are between 0 and 19 degrees Fahrenheit, when the water temperature is below 45 degrees Fahrenheit, when waves are approximately four feet or larger, and when winds exceed 18 knots.
One of the first effects of freezing spray is its ability to ice-over vital lifesaving equipment such as the Electronic Position Indicating Radio Beacon (EPIRB) or life rafts.
The northeastern fishing fleet is no stranger to tragic outcomes caused by the buildup of ice. An investigation of the January 26, 2007, capsizing of the 75-foot commercial fishing vessel Lady of Grace in Nantucket Sound determined that ice accumulation led to a loss of stability and the subsequent sinking of the vessel and loss of her crew of four.
“The most apparent influence an accumulation of ice has on a vessel is on its stability,” said Lt. Garrett Meyer, incident management division chief Sector Boston. “As ice builds on the superstructure of a vessel its ability to right itself after heeling to a side decreases. One of the tell-tail signs that the stability is decreasing is the lengthening of the side-to-side roll period of a vessel. If too much weight is added, factors righting the boat are not strong enough to reverse the roll and the vessel capsizes.”
Meyer said every subsequent inch of accumulation decreases stability more than the previous as every new layer of ice creates more surface area for the next layer exponentially increasing weight. The danger from icing is more than just added weight though; it is often the uneven distribution over the hull of the vessel that amplifies the effect. Even the measures taken by mariners to remove ice may worsen stability problems if ice is only removed from lower portions of the vessel and not from locations higher on the superstructure or rigging.
With forecasted weather conditions for the upcoming week conducive for icing, the Coast Guard urges mariners to remain vigilant, continuously monitor the condition of your vessel, and contact the Coast Guard at the first signs of danger via VHF radio channel 16.
