Walkthrough: After defeating Captain Lana's Trial. you can now explore Brooklet Hill and capture any Pokemon found through. There are also a number of Trainers here that will look to battle you.
Island Scan Pokemon:
Marshtomp
Wild Pokemon:
Initial Pokemon - Daytime (Levels 14-17): Paras(20%), Wingull(20%), Psyduck(20%), Poliwag(20%), Dewpider(20%)
Initial Pokemon - Nighttime (Levels 14-17): Morelull(20%), Wingull(20%), Psyduck(20%), Poliwag(20%), Surskit(20%)
Surfing Pokemon - Daytime (Levels 14-17): Dewpider(40%), Poliwag(40%), Psyduck(20%)
Surfing Pokemon - Nighttime (Levels 14-17): Surskit(40%), Poliwag(40%), Psyduck(20%)
Fishing Pokemon (Levels 10-16): Magikarp(44%), Goldeen(30%), Basculin(25%), Feebas(1%)
Fishing SOS Pokemon #1 (Levels 10-16): Gyarados, Seaking, Basculin, Feebas
Fishing SOS Pokemon #2 (Levels 10-16): Magikarp, Goldeen, Basculin, Feebas
Fishing Bubble Spots (Levels 10-21): Magikarp(40%), Basculin(25%), Goldeen(25%), Feebas(10%)
Bubble Spots SOS Pokemon #1 (Levels 10-16): Gyarados, Basculin, Seaking, Feebas
Bubble Spots SOS Pokemon #2 (Levels 10-16): Magikarp, Basculin, Goldeen, Feebas
Surfing Pokemon (Levels 14-17): Finneon(40%), Tentacool(40%), Wingull(20%)
Fishing Pokemon (Levels 10-16): Magikarp(55%), Wishiwashi(40%), Alomomola(5%)
Fishing SOS Pokemon #1 (Leves 10-16): Gyarados, Wishiwashi, Alomomola
Fishing SOS Pokemon #2 (Levels 10-16): Magikarp, Wishiwashi, Alomomola
Fishing Bubble Spots (Levels 10-21): Magikarp(40%), Alomomola(35%), Wishiwashi(25%)
Bubble Spots SOS Pokemon #1 (Levels 10-21): Gyarados, Alomomola, Wishiwashi
Bubble Spots SOS Pokemon #2 (Levels 10-21): Magikarp, Alomomola, Wishiwashi
Trainers:
Fisherman Ernest - Level 16 Barboach, Level 16 Goldeen
Backpacker Mikiko - Level 16 Fletchling
Fisherman Herbert - Level 16 Poliwag
Fisherman Carl - Level 16 Magikarp, Level 16 Magikarp, Level 16 Magikarp
Fisherman Hal - Level 16 Tentacool
Veteran Johnny - Level 19 Wingull, Level 19 Mantyke, Level 19 Barboach
Items:
Net Ball - Near Totem Site Entrance
X Sp.Atk - Near Backpacker Mikiko
Revive - Near First Body of Water
TM57 - Near Fishman Carl
Rare Candy - Beneath Fisherman (Requires Lapras/Sharpedo)
Hyper Potion - West of Trial Site Entrance
Waterium Z - Complete Captain Lana's Trial
Fishing Rod - Complete Captain Lana's Trial
Dive Ball - Complete Captain Lana's Trial
Elixir (Hidden) - First Patch of Grass
Max Repel (Hidden) - Second Patch of Grass
Post Game
Details: After the Main Story, you can battle Lana at Brooklet Hill after battling her siblings in her house.
Trainers:
Captain Lana - Level 60 Lanturn, Level 60 Cloyster, Level 60 Araquanid