Another one stuck on water hazard

[fatboyjim]

I'm completely stuck in water hazard, I'm faced with a pair of big gates.

I get off the airboat, go up a ladder and kill a guard, then go through a door and kill the guard with the mounted gun hiding behind a blue shield

Walk through the complex for a bit, then finally get to a cog which is broken (which I assume opens the gates)

How do I fix the cog? Or open the gates otherwise?

Thanks
Jim

 

[The Monkey]

You have to shoot at the explsive barrels to your right, then enjoy the show.

 

[fatboyjim]

Nice one! Thanks so much thought I'd be stuck for life :-/