Melville does not have mage hand so he cannot
After a few minutes, Anders comes back down the ladder with a coil of rope and attached hook. "Do you want this Melville? How do you plan to sink the hook against gravity to get to the trident? Just have Rupert throw it?"
"We are going to push the hook through with the ballista bolt, it will takke a few tries I imagine, but once we snag the trident we should be able to pull it at least to this side of the gravity plane."
Melville proceeds to do just that, moving to directly above, or as close to as he can, where the trident is and dropping the grappling hook into the water. Hopefully the momentum of it's fall is enough to carry it a little beyond the gravity plane, where he can nudge it into place with the ballista bolt.
It takes a few tries but after about 10 minutes of mildly frustrating effort, you are finally able to catch the hook around a tine and the shaft of the trident and you are able to pull it up through the water. Even without any other effort Melville and Bazz can feel a mild buzzing magical aura around the weapon.
Rupert will offer to carefully transfer the enchanted trident to their ship, where it can be studied in peace.
Bazz will help any way that he can.
Unless you want to start pulling up floorboards, you all have explored the Wasp ship. Is there anything else you all want to do here, or do you want to plan how to approach the tree?
Do you want to return to the Riposte to do the discussion about exploring the tree?
Melville waits for the Ruposte crew to toss over a line, which he will loop around his waist snugly, before slipping off the side of the wasp into the gravity plane to be hauled in. It isn'tgraceful, but it's safer.
Rupert waves the Riposte in close and will then with rope tied around his waist going to the Riposte, and then tries to jump over to the Riposte.
Athletics Check =[1d20+5]=20+5=25