Diesel-electric submarines are generally quieter than nuclear submarines when running on battery power.[1][2] This is because nuclear submarines require systems like pumps and coolant to operate the nuclear reactor, which generates noise.[1] In contrast, diesel-electric submarines running on batteries have minimal noise from components like shaft bearings and the propeller.[1]
While nuclear submarines are very quiet overall, they cannot match the extreme stealth of modern diesel-electric submarines, especially air-independent propulsion (AIP) submarines that can stay submerged for weeks without snorkeling.[2] The ability of AIP submarines to operate almost silently has allowed them to "sink" nuclear submarines and surface ships in exercises on multiple occasions.[1][3]
However, nuclear submarines have significantly greater endurance and speed compared to diesel-electric boats.[2][4] So while diesel-electric submarines are stealthier for coastal operations, nuclear propulsion provides critical advantages for long-range deployments and high speeds.[4][5]
