through a/the porthole
porthole 常与 through 搭配，表示透过舷窗观看。
She looked through the porthole at the sea.
她透过舷窗看着大海。
舷窗
船或飞机上的窗户；墙壁、船或装甲车辆上的射击孔；炮门；[化] 窥视孔
A circular window set in the hull of a ship.
船或飞机上的窗户
a window in a ship or airplane
墙壁、船或装甲车辆上的射击孔
an opening (in a wall or ship or armored vehicle) for firing through
Standing by the porthole, I watched the waves for over an hour.
我站在舷窗旁，看着海浪看了一个多小时。
用法提示：porthole 是名词，指船上的舷窗，在句中作介词 by 的宾语。
The cabin has two round portholes that let in plenty of sunlight.
船舱有两扇圆圆的舷窗，阳光可以充足地照进来。
用法提示：portholes 是 porthole 的复数形式，在句中作主语。
Through the airplane's porthole, we could see the city lights far below.
透过飞机的舷窗，我们能看见远处城市灯火。
用法提示：porthole 是名词，这里指飞机上的圆形窗户，作介词 through 的宾语。
porthole 常与 through 搭配，表示透过舷窗观看。
She looked through the porthole at the sea.
她透过舷窗看着大海。
也可用所有格表达，如 the ship's porthole。
The porthole of the airplane was small.
飞机的舷窗很小。
grammar · medium
易错句子I opened the porthole in my bedroom to let in fresh air.
正确表达I opened the window in my bedroom to let in fresh air.
porthole 专指轮船或飞机上的圆形舷窗，不是普通的房间窗户；卧室窗户应用 window。
grammar · medium
易错句子He looked in the porthole and saw the ocean.
正确表达He looked out of the porthole and saw the ocean.
表示透过窗户向外看要用 look out of，介词 in 会让人误解为查看窗子本身。
grammar · medium
易错句子There are many porthole on the ship.
正确表达There are many portholes on the ship.
porthole 是可数名词，复数应加 -s；many 后必须用复数形式。
圆形舷窗
The cabin had a small round porthole.
船舱有一个小小的圆形舷窗。
船上的舷窗
Water splashed against the ship's porthole.
海水溅在船上的舷窗上。
从舷窗向外看
He looked out of the porthole at the coastline.
他从舷窗向外看海岸线。
透过舷窗仔细看
The child peered through the porthole at the dolphins.
孩子透过舷窗仔细看海豚。
舷窗外的景色
We enjoyed a beautiful porthole view of the harbor.
我们欣赏到舷窗外美丽的港口景色。
port（船侧开口/入口；同根词 portal 门、入口）+ hole（孔、洞；同根词 keyhole 锁孔、peephole 猫眼）
Dictionary facts from ECDICT, WIKTIONARY.