Seized by the U.S. Navy in 1941 after the Attack on Pearl Harbor, it ferried supplies throughout the Pacific theater and was involved in the Guadalcanal campaign.

It had two diesel engines which spun two propellers with a combined power of 800 horsepower (600 kW),[1] which gave it a maximum speed of 10 knots (19 km/h; 12 mph).

Joaquin Theodore, a tuna fisherman and master mariner, was designated as warrant officer in charge of the ship, despite a complete lack of military training.

The rest of the crew was made up of men with a similar lack of military experience, but extensive maritime skill.

[3] On 3 August, the destroyer USS Tucker was escorting the freighter SS Nina Luckenbach into the Segond Channel.

On 28 August, YP-346 brought a cargo of gasoline to the beachhead at Henderson Field, but had to anchor overnight due to a congestion of supply ships.

At noon the next day, 24 Japanese bombers raided the beachhead, forcing YP-346 to raise anchor and withdraw from the island while still carrying several dozen drums of gasoline.

After distributing the entirety of the ship's food and cigarettes to the embarked Marines, YP-346 joined two other YP boats and three destroyers to make way for Guadalcanal.

After the vessel was beached, PFC John Murphy, who had also been struck by shrapnel, continued to assist other injured sailors onto life boats and then to the nearest aid station on the island.