Singapore’s Otto Marine is suing another charterer over alleged unpaid fees.

Subsidiaries Swordfish 5 and GO Offshore have each started proceedings under the London Maritime Arbitrators Association Terms 2012 against Nigerian operator Vettal Mega Services.

These relate to bareboat charters for the 350-dwt tugs Swordfish 5 and GO ENIF (both built 2010).

Otto alleges the charterer has failed to pay hire of $6m.

“The