In order to calculate the dynamic pressure caused by a fast underwater swimming movement of a diver the following formula can be applied: P = 1⁄2ρv2 Where P is the dynamic pressure, ρ is the density of the fluid and v is the speed. For a fast swimming movement of 10 m/s in typical sea water this works out as: ρ = 1026 kg/m3 v = 10 m/s P = 1⁄2 × 1026 kg/m3 × (10 m/s)2 ≈ 51,300 Pa ≈ 0.5063 atm This calculation shows that fast swimming movements will not create dynamic pressure surges exceeding 0.5 standard atmospheres (51 kPa) (the equivalent of 5 metres of water pressure). ↑ "Citizen Watch Official Site | CITIZEN" (PDF). 7 February 2012.