Many but not all tankers these days do have defensive equipment, e.g. jet sprays, but these probably can't stop too many boats, or if the tanker doesn't have such protection.
If you have a hose that you can fire from a fairly protected position and the guy with the RPG is completely exposed because he's trying to climb up the side of a tanker, yeah, I might.
See, the hijackers can't actually sail the ship. So they can't kill the crew, or at least can't kill very many of them.
> If you have a hose that you can fire from a fairly protected position and the guy with the RPG is completely exposed because he's trying to climb up the side of a tanker, yeah, I might.
In this scenario you are standing on a ship that is full of highly flammable oil.
There are more outcomes than just the hijackers gain control of the ship or they leave you alone.
If gaining control is no longer an option they could decide "fuck it" and just fire into the side of your hull.