Kalgor
After several futile attempts to snag the glowing key at the bottom of the pool, Kalgor gets frustrated. "Oh, alright." He gets undressed down to a loin cloth, belt, scabbard, dagger and a drawstring pouch on his belt. He places his whetstone in the his pouch of sling bullets, and ties that pouch and the grappling hook to the rope. "At least these should drag me down there easier." Handing Iosef the other end of the rope, "You get to pull me back up if I don't float."
He fashions a sack out of a pillow case, and ties that to the rope also, with a half open mouth for the sack. "The bulk of the keys will go in there."
Sitting on the edge of the pool, he casts Dancing lights and sends them down to the bottom four corners of the pool. Then, casting Detect Magic and taking a deep breath, he goes in. Holding onto the ballast, he sinks to the bottom quickly.
Once at the bottom, with one hand holding the ballast, he grabs the magical key and puts it into the drawstring pouch and pulls it closed. Then, he quickly scoops up the rest of the keys and any coins down here, placing them in the pillow sack attached to the rope. After grabbing everything, he lets go of the ballast, and pushes off the floor back to the surface, pulling on the rope to speed him up.
Once back at the surface, "OK big guy, you can pull up the mundane loot" as he climbs out of the pool.
Casting Prestidigitation, and then shaking like a mangy mutt, he is all of the sudden dry.
[sblock=actions] 15 lbs of stone and iron ballast to get me down easier. Only a belt, dagger and one key holding me down while coming back up with both hands free "climbing" the rope.[/sblock]