Thanksgiving Day and the whole holiday weekend look promising for fishing. Tolerable wind velocities should allow boaters to hit the open waters and, with a predicted wind direction shift to the east, the marshes and back bays will begin to fill with fresh saltwater.
No doubt that the recent blast of cold air helped the flounder run. The larger females are making their move. The areas from which the fish were driven should refill quickly, which might slow down the exodus as fish return to their habitat until the next spell of strong northerly winds.
While there were no fishing reports from the cold, rainy and windy weather Monday and Tuesday, this presents an opportunity to address some frequent questions by readers.
One of the most common questions deals with the term “knot” as used in wind velocity. Two questions that are asked most often are what is the definition of a knot and how did the term originate?
The knot is a unit of speed equal to one nautical mile or about 1.151 mph.
When you hear of wind velocities or the speed of a vessel, multiply the knot speed by 1.151 to translate to mph.
The term originated during the era of the ancient mariners from counting the number of knots in the line that unspooled from the reel of a chip log in a specific time.
The knots were placed at a distance of 47 feet, 3 inches and passed through a sailor’s fingers while another sailor used a 30-second sand glass to time the speed of the knots passing behind the boat.
The knot count would give them the speed of the vessel and was used in “dead reckoning” and navigation. The number of knots that passed during the 30-second time frame determined how fast the boat was traveling in nautical miles per hour.
For example, if 10 knots passed through in 30 seconds, it was concluded that the vessel was traveling 10 knots per hour, or 11.51 mph.
Today, many GPS systems give distances to waypoints in nautical miles. The captain must multiply that number by 1.151 to obtain the distance in statute miles.
No comments:
Post a Comment