I would have one in my Diamond team but Gyarados is part flying and no good non-legendaries that are avalable can learn surf or fly pre-post-game. My team is now be Empoleon, Rampardos, Honchkrow, Gengar, Snorlax and Alakazam.

Favorite Water-type Pokemon. It has a great Atk. stat and can learn most of the TMs. The downside is its double weakness to Electric and about half of the TMs it can learn is Special-based which renders the great Atk. stat redundant. A preferable moveset would be:

Ice Fang (good coverage)

Waterfall (or Dive, STAB move)

Stone Edge (good coverage and high critical chance)

Earthquake (Electric-type bane, as well as Steel, Rock and Fire)

Note: Replacement of Waterfall with Dive will only mean one turn longer battle and no chance to flinch.

it can learn flame thrower for fun

Sure but my recommendation was completely tactical. If challenged a battle facility with a Gyarados that knows Flamethrower, that would make a poor moveset.

Why not outrage?? I freaking love the move outrage!!!!!

Gyarados is da BEAST!!!!!!!!!!!!!!!!!!!!!!

if there was a pokemon football team it should be team gyarados