Mh, maybe, but it has chlorophyll. It can essentially achieve 480 speed under Sun. Not bad, what?
Anyways, I think Sealing needs an evolution. Call it Marinarch (Marine+Monarch. It'll be far from kingly, but what's in a name? That which we call a feesh will be just as dumb by any other...)
MARINARCH
Type: Water
Abilities: Swift Swim / Lightning Rod / Water Veil (unchanged)
HP: 80 --> 100
Atk: 92 --> 117
Def: 65 --> 85
SpAtk: 65
Spdef: 80
Speed: 68 --> 88
Poor old seaking is a horrible, dumb looking Pokemon. It might as well have been called Seaslave, and been more honest on its Resumé. But all that changes with an evolution that can help it hope to be a legitimate threat.
The evolution, Marinarch, gets a good buff to its HP, Speed and Defense, while improving its decent Attack stat to current (heh) levels. Now, although its Special Attack remains too poor to utilise Lightning Rod offensively, it is still excellent defensively to counter Electric types and foil the BoltBeam combination popular in Balance today. It even has Drill Run to hit Electric types for a hefty chunk, along with a surprisingly good physical movepool including Waterfall, Knock Off and Megahorn (which also lets it strike at Grass types.) If it wishes to take a more offensive role, it now has the speed to abuse Swift Swim well; at abase of 88, it rivals Sand Rush Excadrill and both outpaces and out-powers (at least on the physical side) Kingdra in the Rain! Although it lacks Dragon Dance or Swords Dance, it can still make some use of its raw stats to good effect in UU, (though it is still beaten by Kabutops, which gets SD and Stone Edge, and Seismitoad, which is fatter and has a better typing, and Mega Swampert, which is just better in every way save for its inability to hold an item.)