rkr3000
Guest
I've been drift diving several times, but I can't seem to get a clear definition of exactly how fast the current is when it is something like "8 knots". How fast is a knot compared to miles per hour? Just curious.
drift diving question
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ArcticDiver
Contributor
A Knot is 1 Nautical Mile Per Hour. If memory serves a Nautical Mile is 6000 feet.
A Mile Per Hour is, 1 Statute Mile Per Hour. If memory serves a Statute Mile is 5280 feet.
A Mile Per Hour is, 1 Statute Mile Per Hour. If memory serves a Statute Mile is 5280 feet.
rkr3000:
If your diving 8 knots are you seeing anything other than a blur? Thats Around 9.2 mph. :11:
Gary D.
8kts is "hold on for dear life or preferably get out of the water ASAP before you smack into a rock and/or lose mask and reg"/
Think of it in terms of current and even a 1kt current is too much to swim against constantly without getting tired. 2 or above, forget it - its taking you for a ride.
Typically here we could see 4 or 5kt currents at times, these arent too much fun to dive when visibility is typically 3-5m as you cant see obstructions. Also arm aches like hell holding the reel attached to SMB.
Think of it in terms of current and even a 1kt current is too much to swim against constantly without getting tired. 2 or above, forget it - its taking you for a ride.
Typically here we could see 4 or 5kt currents at times, these arent too much fun to dive when visibility is typically 3-5m as you cant see obstructions. Also arm aches like hell holding the reel attached to SMB.
8 knots, wow. I have been in many currents and drift dives. I don't even try to gues how fast. but I would agree with previous posts. A knot or two is a nice ride, three or four and your flying.
Couldnt you watch a stationary object as you pass over it, guess a distance and measure a time to roughly put together a current speed? 8 knots is a pretty decent current!
donacheson
Contributor
ScubaRon:
A meter was originally defined as 1 ten-millionth of the distance from equator to pole (at sea level) and the nautical mile as the length of 1 minute (1/60th of a degree) of arc on a sphere with the same surface area as the earth (which is slightly flattened so that the equatorial radius is slightly larger than the polar radius).
For convenience, the nautical mile is now defined as exactly 1852 meters.
one knot is 0.514 meters per second.that makes 8 knots 4.11 m/s or 13.5 feet per second, which is really quick.
The term knot came from when the log "a bit of wood" tied onto a string was tossed overboard a sailing ship. The length of string was measured by the knots tied in the string. I figure that there must have been a knot in the string about every hundred feet if they timed it for a minute.
If they timed it for only fifteen seconds, then the knots in the string would have been only four fathoms apart.
The term knot came from when the log "a bit of wood" tied onto a string was tossed overboard a sailing ship. The length of string was measured by the knots tied in the string. I figure that there must have been a knot in the string about every hundred feet if they timed it for a minute.
If they timed it for only fifteen seconds, then the knots in the string would have been only four fathoms apart.
Dave_1985
Guest
cancun mark:
on the subject of nautical measurement, how long is a fathom?
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