I'm pretty sure that you don't need surf to get there.
You get Surf after defeating Cheren at Twist Mountain.
Surf is given to you by Champion Alder at Twist Mountain
Alder the champion will give it to you on Twist Mountain.
Alder gives it to you when you get to twist mountain
a person at twist mountain will give it to you after you beat the gym fly gym i think...
the champion gives it to you before you enter twist mountain after beating cheren
When you have beat your friend at twist mountain the champion was watching on the cliff and he jumps down.Then he gives you the HM03(surf).
you get from alder at twist mountain.
It's on Twist Mountain where Alder will give it to you.
You must: 1. Beat the 6th gym leader. 2. Go to Twist Mountain 3. Before you go in, Clay, the 5th gym leader, will give you surf.
You receive the HM surf after defeating Cheren at Twist Mountain (Route 7). Alder, the Champion of the Unova region, will give Cheren HM03. And he will say "Here-you too." and give you HM03-Surf.
get to the pint in the game where u need to go into twist mountain. at the begining of twist mountain, the champion of the unova region (Alder) comes out and givs surf to u. good luck!