When you are on the pirate planet [planet name] you will eventually reach a point where your ship is locked into the plunder beam and the objective will require you to disable the plunder beam.
The way forward is not crystal clear so for anyone who is stuck on this quest objective, here is what you need to do to disable the plunder beam.
The video guide below will show you the way to go to disable this as quickly as possible.
You will need to return to the central area of your ship. On one side you will see another ship and the other is a small island like thing that is sticking out of the water. There may be few enemies here that are shooting at you. You will need to speed up on the hover boots and leap over to this platform.
Once you are on this platform, keep an eye out for the pirate boats that are flying overhead. On the back of all of these ships is a grapple point. You will be able to latch onto this and the boat will carry you up to the main ship that is firing the plunder beam on you.
The objective will show you what you need to destroy when you get up here. Once the beam is down, you can return to the ship and continue on with the mission.