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

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.

Yard per hour measures distance in yards traveled over one hour. Rarely used except in specialized contexts.

1 yd/h = 0.000254 m/s = 0.0009144 km/h = 0.9144 m/h.

To yd/min: ÷ 60. To ft/h: × 3. To m/h: × 0.9144.

No common modern applications. Might appear in some historical documents.

No notable facts — too rarely used.

Even existing is a mistake — use m/h, ft/h, or mph instead.

1,760 yd/h = 1 mph. Extremely uncommon. Better to use other units.