Okay I will complie data I gather about water pokemon training, and breeding.
I consder my self a water pokemin expert so I am sure my data will be intresting.
In my posts I will also note what versions my data comes from to make it easy to apply and keep track of.
Stat wise Gyarados is a very solid pokemon with no real weaknesses.
Its defense and special attack are actually its weakest stats, and attack is its biggest.
That being the case physical moves will do more damage then special attack based ones even if the have more move based power by a margin of nearly 30%.That being the case the three moves best suited to Gyarados are, Aqua Tail, Waterfall, and Hyper Beam. Aqua Tail and Waterfall are especial good because the are physical moves, and water type benefiting form Gyarados's water type nature. And Hyperbeam though not water type is so fundamentally destructive that with Gyarados's High attack it should pretty much be able take out an opponent's HP from about half or more.
Now for some stat info based on Heart Gold and Soul Silver based version, others to be added later.
Caracteristics that are most desirable: Proud of its power, Likes to thrash about, A little quick tempered, Likes to fight, Quick tempered, Highly Curious, Mischievous, Thoroughly cunning, Often lost in thought, Very finicky.
Moves and levels learned.
Low level wild Gyaradoses Come with the move Thrash not learnded by a Gyarados evolved form a Magikarp.