Table 4 Matrix showing the difference in speed over ground, broadband (5–1000 Hz) source level, and sound exposure level (SOG (m s⁻¹)|SL (dB re 1 μPa² @1 m)|SEL (dB re 1 μPa²s)). Asterisks show degree of significance (p < 0.05 = *, p < 0.01 = **, p < 0.001 = ***). Light grey cells show the difference in means between award tiers while the fleet-based vessel speed reduction program was active. Dark grey cells show the difference in means between award tiers while the fleet-based vessel speed reduction program was inactive. White cells show the difference in means within an award tier while the fleet-based vessel speed reduction program was active v. inactive.

From: Underwater noise mitigation in the Santa Barbara Channel through incentive-based vessel speed reduction