小艇吊杆 boat derrick ; boat hoist ; launching derrick

救生艇吊杆绞辘 life boat tackle

吊艇杆 [船] boat boom ; boat derrick ; [船] boat spar ; submarine boom

吊艇铁杆 hoisting rod

吊艇杆软梯 boat ladder

舷边吊艇杆 riding boom

挂在吊艇杆上的软梯 boat ladder

艉吊艇杆 quarter boom

挂在吊艇杆的软梯 boat ladder