舷門 is read as げんもん (gemmon) and means gangway.
げんもん
gemmon
もん
branch of learning based on the teachings of a single master
ぶもん
division (of a larger group)
にゅうもん
entering through a gate
めいもん
prestigious school, organization, business, etc.
せんもん
sole interest
と
door (esp. Japanese-style)
かんもん
barrier
せいもん
main gate
おおもん
large front gate
いちもん
group of related sumo stables
こうもん
school gate
しゅうもん
(religious) denomination