Surf: Honeycalm Island (1%), Honeycalm Sea (1%), Insular Sea (1%) + 2 more
Max Raid Battle: Honeycalm Sea (Only in Shield), Insular Sea (Only in Shield), Stepping-Stone Sea (Only in Shield) + 1 more
Its base catch rate is 55 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Dream Ball, Heal Ball or Master Ball.
Evolution: Skrelp → Dragalge (Level 48).
Dragalge in every game · Pokémon Sword & Shield interactive map (Galar)