Coral Scorpionfish
Scorpaenodes corallinus
(1-2: Pahoehoe Beach, Kona)
Decoy Scorpionfish
Iracundus signifer
(1: Pawai, Kona / 2: Pinnacles, Oahu)
Devil Scorpionfish
Scorpaenopsis diabolus
(1: Three Fingers, Kauai / 2: Garden Eel Cove, Kona / 3-4: Mario World, Oahu / 5: Turtle Canyons, Oahu / 6: Koko Craters, Oahu / 7: First Cathedral, Lanai / 8: Vertical Awareness, Lehua)
Images 2, 4, and 6 all have pairs of scorpionfish.
Be careful where you put your hands at night. I almost sat on this one during a manta ray dive:
Hawaiian Coral Croucher
Caracanthus typicus
(1: Mala Pier, Maui / 2: First Cathedral, Lanai / 3: Amber's Arches, Kauai / 4: Hale O Honu, Kauai)
Shy little fish. In the second picture, it's to the lower left.
Hawaiian Red Lionfish
Pterois sphex
(1-3,6-8: Amber's Arches, Kauai / 4-5: Cliffhanger, Kauai)
This is native to Hawaii. It's not an invasive species, like the red lionfish is in the Caribbean.
Leaf Scorpionfish
Taenianotus triacanthus
(1: Golden Arches, Kona / 2: Lighthouse, Lanai / 3: Fast Lanes, Kauai / 4: Corsair, Oahu / 5,7: Mala Pier, Maui / 6: First Cathedral, Lanai / 8: Moray Eel Cove, Kona)
Shortsnout Scorpionfish
Scorpaenopsis brevifrons
(1: Shark Fin, Lanai / 2-3: Kaloko Arches, Kona)
Speckled Scorpionfish
Sebastapistes coniorta
(1: Pawai, Kona / 2: Kahalu'u Beach Park, Kona / 3: Hoover's, Kona / 4: Turtle Canyons, Oahu / 5-6: Mala Pier, Maui / 7: Pahoehoe Beach, Kona)
There are at least three of them in the 2nd picture.
Titan Scorpionfish
Scorpaenopsis cacopsis
(1: Sheraton Caverns, Kauai)