Convert from nautical mile/hour to speed of light [water]

Unit Definition (nautical mile/hour)
The knot is a unit of speed equal to one nautical mile per hour. Its kn abbreviation is preferred by American and Canadian maritime authorities, the Institute of Electrical and Electronics Engineers, and the International Bureau of Weights and Measures, however, the kt (knot) and kts (knots) abbreviations also are used. The knot is a non-SI unit accepted for use with the SI. World-wide, the knot is used in meteorology, and in maritime and aviation navigation — for example, a vessel travelling at 1 knot along a meridian, travels one-sixtieth of a degree of geographic latitude in one hour. Mariners first used the term knot denoting the measure of how many knots of line paid out in a given time using the chip log

Unit Definition (speed of light [water])
The speed of light in a vacuum is exactly equal to 299,792,458 metres per second (approximately 186,282.4 miles per second). The speed of light is denoted by the letter c, reputedly from the Latin celeritas, "speed", and also known as Einstein's constant. This exact speed is a definition, not a measurement, as the metre itself is defined in terms of the speed of light and the second.