Generally, underwater noise is becoming worse, keeping in mind that areas, as the Arctic, are having an increased shipping traffic nowadays.

The International Workshop on Shipping Noise and Marine Mammals, held in Hamburg back in 2008, highlighted that with the advent of modern shipping, low-frequency ocean noise has been doubling approximately every decade.


Despite the urgency of finding a solution to this problem, RINA supports that it hasn't got much attention in comparison to other 'maritime matters'. However, the IMO, EU and other regulatory bodies have recently raised the bar, with the aim of making the transport of goods and passengers more environmentally friendly.

To decrease the underwater noise coming from ships, the industry should understand that each vessel, individually, plays an important role.

Thus, RINA Dolphin is an additional class notation, launched by Rina, that focuses on the marine environment; It consists of two limits, concerning commercial vessels:

  1. DOLPHIN Transit, for normal seagoing conditions. This is aimed at reducing overall global noise from shipping.
  2. DOLPHIN Quiet, for ships travelling at 10 knots. This applies to areas of high environmental importance, for example areas with a high concentration of marine mammals.

The Class notes that the noise limits are according to the underwater radiated noise measurements of ships and the results coming from researches in the area.