Surf is the thoughest HM. It's useful because I can pass accros the water. My palkia has high special attack and I think I should forget him aqua tail and replace it with surf.
Should I do it?
I don't see why not...
Surf isnt a bad move itself, and since it is STAB on the top of whay you said, it should be a good move to include in Palkias moveset.
Surf has more accuracy than Aqua Tail and slightly more power. If your Palkia has high Sp.Attack, this would be the
perfect Water-type move for it.Surf also lets you go across
water outside of battle.It has STAB,too.
Also palkia , http://pokemondb.net/pokedex/palkia
has a higher base sp.attack than attack and so at all points your palkia using surf would be much more deadly !!
SuperFlygon has it on the spot. Surf is a great STAB move for Palkia and it is really effective with 95 attack power and with Palkia's high special attack. Great choice for wiping out opponents
Hope this helps =)