The crew of a Tidewater platform supply vessel (PSV) was reported safe on Thursday following a pirate attack off Nigeria.
EOS Risk Group said gunmen boarded the 4,700-dwt Saavedra Tide (built 2016) while it was en route to the Egina FPSO on Tuesday.
It added: "The likely modus operandi is kidnapping for rescue, but with the crew allegedly locked inside the citadel, the [pirates] may attempt to attack other vessels nearby until a successful hijacking is achieved."
EOS said hijackers left the vessel the same evening.
A Tidewater spokesman confirmed the incident to Offshore Energy Today, and said the ship and crew returned safely to port.
Kidnapping raids for ransom have increased off West Africa in recent months.
