Profile, Abilities and Weaknesses description from The Transformers G1 series by Marvel Comics.

Profile: Seawing is the eeriest, most ominous Seacon -and he knows it.
He glides through the ocean' depths like a sinister steel specter, spreading fear among all who see him. This pleases him greatly. "Who better to rule than he to whom all bow," he reasons.  Some Decepticons speculate that Seawing's ambitions go beyond the Seacons and reach to Decepticon Command itself. Not denying this; Seawing does much more to achieve his goals than merely frighten some tin-scaled robo-fish. He is an expert at his job, and he enjoys every moment of it. Once he zeroes in on a target, he uses his wits to surprise and then his armaments to destroy. And underwater, nothing escapes his notice, or his grasp.

Abilities: In manta ray mode, Seawing employs a battery of sensors -electrical, chemical, infrared and long-range sonar in his reconnaissance missions. His sensitivity is such that he can locate a screw head on the ocean bottom up to 20,000 feet below him. He can detect and home in on anything living or moving in the water within a 20-mile radius. His maximum speed is 110 mph. In manta and robot' modes, he is equipped with two venom lasers which shoot beams that paralyze on contact. In weapons, station mode, he combines with the lasers to become a powerful dual proton blaster. He combines with his fellow Seacons to form the super-robot, Piranacon.

Weaknesses: In. manta ray mode, Seawing's optical modules are adjusted to pick up the very dim light that reaches the ocean depths. As a result, he is very sensitive to bright light, and is easily blinded by sudden flashes underwater.

Bibliography of significant appearances: 
* (Marvel) Transformers #47- All members of the Decepticon Seacon team are seen hunting the pirate treasure off the shores of "Club Con" in this episode.
* (Marvel) Transformers #49- Under the command of (gulp, I can hardly say it) "Commander Ratbat," The Seacons unite into Piranacon.
* (Marvel) Transformers #50 - The Seacons get a very brief cameo appearance in trying to lay a smackdown to a soon to be Underbase powered Starscream.
* a few additional cameo appearances in a couple Marvel UK comics, including UK #268 where the team is (relatively speaking) featured.

Other Appearances: