Velocity of Sound in Sea Water (20°C, 10m depth) to Mile per Second

The speed of sound in seawater at 20°C and 10 meters depth is approximately 1,522 m/s, varying with temperature, salinity, and pressure.

Complex function of T, S, P. Mackenzie equation: c ≈ 1,449 + 4.6T - 0.055T² + 0.00029T³ + (1.34-0.01T)(S-35) + 0.016z. Typical: ~1,500 m/s.

To km/h: × 3.6. To ft/s: × 3.281. 1,522 m/s = 5,479 km/h = 3,404 mph.

Naval sonar, commercial ship echo sounders, underwater positioning systems, and marine seismic surveys.

Sound speed increases ~1.3 m/s per °C, ~1.3 m/s per PSU salinity, and ~1.7 m/s per 100m depth. SOFAR channel at ~1000m depth traps sound for thousands of km.

Using a single constant — sound speed in the ocean varies significantly with depth and location. Always measure or calculate for local conditions.

~1,500 m/s is a good approximation. Remember: warmer, saltier, deeper = faster sound. Critical for accurate sonar ranging.

Mile per second measures statute miles traveled in one second. An extremely high speed unit used for spacecraft, missiles, and astronomical phenomena.

1 mi/s = 60 mi/min = 3,600 mph = 1,609.344 m/s = 5,793 km/h.

To mph: × 3,600. To km/h: × 5,793. To m/s: × 1,609.344.

Earth's orbital speed: 18.5 mi/s. Moon's orbital speed: 0.64 mi/s. Space shuttle orbital: 4.9 mi/s. Escape velocity: 6.95 mi/s.

Earth escape velocity: 6.95 mi/s (11.2 km/s). Solar escape (from Earth): 26 mi/s. Fastest spacecraft (Parker Solar Probe): 120 mi/s peak.

Underestimating how fast this is — 1 mi/s is 3,600 mph, incredibly fast. Confusing with mi/min (60× slower).

Think 'space speeds in miles.' 1 mi/s ≈ 1.6 km/s. To escape Earth: ~7 mi/s. Orbital speed: ~5 mi/s.