Move away from the quay and start attacking the shrimps that will be coming in waves. As was stated before, it is best to use here a shotgun, or any other weapon effective at close quarters. Aim at their heads and remember not to waste your ammo while they are hiding behind their armors.
Wait for the wench to activate and press the red button to call for the ferry. Soon, the green monster that you have encountered while exploring the lane wreck, will emerge from water. It is necessary that you move away from the beast, due to its long limbs which it can use to deal heavy damage at a large distance. Try and remain in constant motion now and to take cover every time the monster charges at you.
A good piece of news is that you do not have to fight the monster until it drops dead, because soon it will be attacked by a demon that arrives in the area. Move away and let the demon chase the large shrimp away, which will unblock the passage to the ferry.
Keep watching the quayside and, as soon as the ferry arrives, run onto it and pull the lever, thus ending this exhausting chapter.