Walkthrough: At the end of Seaward Cave, you will come to Kala'e Bay. Here, you can find loads of Wild Pokemon, especially those of Water Typing.
Island Scan Pokemon:
Horsea
Wild Pokemon:
Initial Pokemon - Daytime (Levels 15-18): Wingull(40%), Yungoos(30%), Slowpoke(20%), Bagon(10%)
SOS Pokemon #1 - Daytime (Levels 15-18): Wingull, Yungoos, Slowking, Shelgon
SOS Pokemon #2 - Daytime (Levels 15-18): Wingull, Yungoos, Slowbro, Shelgon
SOS Pokemon #3 - Daytime (Levels 15-18): Wingull, Yungoos, Slowbro, Bagon
SOS Pokemon #4 - Daytime (Levels 15-18): Wingull, Yungoos, Slowpoke, Bagon
Initial Pokemon - Nighttime (Levels 15-18): Wingull(40%), Rattata(30%), Slowpoke(20%), Bagon(10%)
SOS Pokemon #1 - Nighttime (Levels 15-18): Wingull, Rattata, Slowking, Shelgon
SOS Pokemon #2 - Nighttime (Levels 15-18): Wingull, Rattata, Slowbro, Shelgon
SOS Pokemon #3 - Nighttime (Levels 15-18): Wingull, Rattata, Slowbro, Bagon
SOS Pokemon #4 - Nighttime (Levels 15-18): Wingull, Rattata, Slowpoke, Bagon
Surfing Pokemon (Levels 15-18): Tentacool(40%), Mantyke(20%), Finneon(20%), Wingull(20%)
Surfing SOS Pokemon #1 (Levels 15-18): Tentacool, Remoraid, Finneon, Wingull
Surfing SOS Pokemon #2 (Levels 15-18): Tentacool, Mantyke, Finneon, Wingull
Fishing Pokemon (Levels 10-17): Wishiwashi(35%), Magikarp(35%), Remoraid(25%), Shellder(5%)
Fishing SOS Pokemon #1 (Levels 10-17): Wishiwashi, Gyarados, Octillery, Shellder
Fishing SOS Pokemon #2 (Levels 10-17): Wishiwashi, Magikarp, Remoraid, Shellder
Fishing Bubble Spots Pokemon (Levels 10-22): Shellder(35%), Wishiwashi(25%), Magikarp(25%), Remoraid(15%)
Fishing Bubble Spots SOS Pokemon #1 (Levels 10-22): Shellder, Wishiwashi, Gyarados, Octillery
Fishing Bubble Spots SOS Pokemon #2 (Levels 10-22): Shellder, Wishiwashi, Magikarp, Remoraid
Items:
Dive Ball - Near Seaward Cave Entrance
Hyper Potion - North East Island
TM05 - South Part of Large Mass
Prism Scale - Southernmost Area
Star Piece (Hidden) - Middle of Pool At Top of Beach Mass
Pearl (Hidden - Daily) - Southwest of Beach
Big Pearl (Hidden - Daily) - Middle of Southernmost Island