Captain Cutler's Ghost was the disguise of Captain Cutler.
Captain Cutler was dressed in a glowing light green deep sea diving suit that was covered in manky seaweed and chains.
Scooby-Doo, Where Are You! Edit
Captain Cutler's Ghost was the "ghost" of Captain Cutler who one dark, foggy night collided with a yacht and followed his ship down to the ocean floor. After a while he began to haunt Rocky Point Beach and take his revenge to the yachts at the marina by making them disappear. He is dressed in a glowing diving suit and leaves glowing footprints wherever he goes from a type of seaweed found only in Graveyard of Ships.
http://scoobydoo.wikia.com/wiki/Scooby-Doo_2:_Monsters_Unleashed Scooby-Doo 2: Monsters Unleashed][http://scoobydoo.wikia.com/index.php?title=Ghost_of_Captain_Cutler&action=edit§ion=8 Edit
He was activated when Shaggy and Scooby were doing dumb things to the control panel causing some of the monsters to come to life, including Captain Cutler himself. When the gang went down to the old high school clubhouse they didn't know that Captain Cutler was in the water. While Fred, Velma and Daphne were working on the control panel Shaggy and Scooby were outside near the Mystery Machine when Shaggy and Scooby walked over near the water when Shaggy said "We can be heroes and save the day" and then said "You know what we can do right" and picks up a rock from the ground and skips it across the water until it hit something metal underneath the water. Then bubbling sounds and a glow began to rise out of the water Shaggy stared in horror as they saw Captain Cutler's Ghost and he said "Captain Cutler's Ghost" and the ghost made a moaning sound then Shaggy yelled "Captain Cutler's Ghost" when Fred said "they found us we got to get this thing back to the Monster Hive" and which the gang headed for the Mystery Machine and the ghost made a loud moaning sound as he climbed out of the water and took out his spear gun and fired it at the Mystery Machine and then started pulling it backwards. The gang asked what they were going do, then Fred said "Fine let's go back" and then backed up the Mystery Machine and then just like that Cutler's body made a loud splash sound as it hit the water. Captain Cutler was killed when Scooby-Doo reconnected the control panel in the Monster Hive.