KNOTS vs. MILES

Good morning.

We get lots of suggestions and questions from our Daily Vitamin users, which we try to include in one of our lessons as soon as we can. Today I want to answer a suggestion from Narcís Ferrer that was sent to us right before summer.

Perhaps it is a good idea to explain the differences between miles and knots
Best regards, Narcís

A knot is a unit of speed and is very similar to miles per hour (mph). Below I have summarised the difference.

NOTE: this explanation is simplifying quite a bit, and I'm not a nautical expert. For more information see Wikipedia: http://en.wikipedia.org/wiki/Knots.

DISTANCE
Mile = 5,280 feet or 1,609 metres
(that's five thousand two-hundred and eighty feet or one thousand six-hundred and nine metres).

Nautical Mile = 6,080 feet or 1,852 metres

SPEED
1 international knot = 1 nautical mile per hour = 1.852 kilometres per hour exactly.

One knot (1 nautical mile per hour) = 1.15 mph

Therefore, if a boat is travelling at 20 knots, it is travelling at approximately 23 miles per hour ground speed (20 x 1.15 mph = 23 mph).

When I was a boy, I was always told that a knot is the same as a mile per hour, but on water. I suppose no one wanted to try to explain this difference to me, or didn't even know. In any case, there is very little difference.

Thanks for the question Narcís.

Have a nice day.