World Record Title: The longest tunnel in the world's seabed is the British and French subsea tunnels.
World Record Creator: The British and French subsea tunnels
World Record Holder: The British and French subsea tunnels
World Record Field: Subsea tunnelsl
World Record Rules: The longest tunnel in the world's seabed.
World Record Number: 20121100007
World Record Validity Period: Until the world record was broken.
World Record Witness: Carrying the Flag World Records certifier 001
World Records Source: World record database of Carrying the Flag
Awarding Certificate Date: November 11, 2012
World Record Details:

          The longest tunnel in the world's seabed is the British and French subsea tunnels. (Total length:50.45 km, length undersea section: 37.9 km)