Same as gang-board, Gang-plank is the usual word in the United States.(noun)
The Century Dictionary (Public Domain)
Use "gang-plank" in a sentence
"When Daughtry sauntered along the main deck a few minutes later and paused for a gossip with the customs officer and a quartermaster at the head of the gang-plank, Captain Duncan little dreamed that his casual glance was resting on his steward for the last time."
"He watched him go down the gang-plank empty-handed, with no dog at his heels, and stroll off along the wharf under the electric lights."
"The gang-plank being on the port side, Dag Daughtry paddled around to the starboard and brought the canoe to a stop under a certain open port."