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

Yard per second measures distance in yards traveled in one second.

1 yd/s = 0.9144 m/s = 3.29 km/h = 2.045 mph = 3 ft/s.

To ft/s: × 3. To m/s: × 0.9144. To mph: × 2.045.

Sprint speeds in track and field (10–12 yd/s for elite sprinters), projectile velocities, and some fluid flow measurements.

Usain Bolt peak: ~13.5 yd/s. NFL wide receiver sprint: ~11 yd/s. Baseball thrown: ~40–45 yd/s.

Confusing with ft/s — yd/s is 3× faster. Mixing up with mph.

1 yd/s = 3 ft/s = 0.9144 m/s. Multiply by ~2 to get approximate mph.