This 30 floor dungeon is unlocked by purchasing the Serene Sea Friend Area. The HM Dive is required to enter the dungeon.
| Name | Type | Level | EXP | Levels seen | Recruit Rate |
|---|---|---|---|---|---|
| Wingull | 23 | 1-5 | 12.5% | ||
| Tentacool | 25 | 1-9 | 8.3% | ||
| Qwilfish | 30 | 1-9 | 6.9% | ||
| Kabuto | 28 | 5-13 | 7.2% | ||
| Corsola | 27 | 5-13 | 8.3% | ||
| Slowpoke | 25 | 6-14 | 12% | ||
| Horsea | 29 | 10-20 | 12.4% | ||
| Dragonite | 24 | 10, 15, 20, 25 | N/A | ||
| Anorith | 26 | 14-23 | 8.7% | ||
| Krabby | 32 | 15-20 | 8% | ||
| Staryu | 28 | 15-25 | 8.9% | ||
| Vaporeon | 22 | 20, 30 | N/A | ||
| Tentacruel | 33 | 21-30 | -30% | ||
| Kabutops | 33 | 24-30 | N/A | ||
| Slowbro | 27 | 25-30 | N/A | ||
| Kingler | 35 | 25-30 | N/A | ||
| Seadra | 20 | 27-30 | -19% | ||
| Mantine (red only) | 15 | 30 | 9.5% |