Tuso is great for these as they usually hide in the little plants on the sea floor, and the tuso’s tentacles will hit basically all of that without you getting in attack range, if you don’t have a tuso I recommend using a beezlebufo, fast and does bonus damage to them
Be very careful about these-they do tons of torpor damage, I was down on the bottom of the ocean (on the island) and I saw a pack of these sea scorpions. I decided to dismount off of my mosa and kill them with my pick, as that would get more black pearls. When I got close to them one of them-a level ten hit me and knocked me out in one shot. I was level 88, wearing journeyman flak and apprentice riot. And they knocked me out in one hit. The moral of the story is that these things are very dangerous.