* On the small island southwest of the Seafloor Cavern Dive spot ''(hidden)''
* On the small island northeast of the Seafloor Cavern Dive spot, near {{tc|Ace Trainer|Cooltrainer}} Alexa{{sup/3|Ru}}{{sup/3|Sa}}/Ruben{{sup/3|E}} ''(hidden)''
* On the island directly east of the Seafloor Cavern Dive spot ''(hidden)''
* On the island directly east of the Seafloor Cavern Dive spot ''(hidden)''
* On the small island northeast of the Seafloor Cavern Dive spot, near {{tc|Ace Trainer|Cooltrainer}} Alexa{{sup/3|Ru}}{{sup/3|Sa}}/Ruben{{sup/3|E}} ''(hidden)''|Ru=yes|Sa=yes|E=yes|display={{DL|Exchangeable item|Heart Scale}} ×3}}
* On the small island southwest of the Seafloor Cavern Dive spot ''(hidden)''|Ru=yes|Sa=yes|E=yes|display={{DL|Exchangeable item|Heart Scale}} ×3}}
{{Itemlist|Protein|In a rock in the small {{m|Dive}} spot at the center of the ring-shaped island ''(hidden)''|Ru=yes|Sa=yes|E=yes|display={{DL|Vitamin|Protein}}}}
{{Itemlist|Pearl|In a rock in the easternmost {{m|Dive}} spot ''(hidden)''|Ru=yes|Sa=yes|E=yes|display={{DL|Valuable item|Pearl}}}}
{{Itemlist|Pearl|In a rock in the easternmost {{m|Dive}} spot ''(hidden)''|Ru=yes|Sa=yes|E=yes|display={{DL|Valuable item|Pearl}}}}
{{Itemlist|Protein|In a rock in the small {{m|Dive}} spot at the center of the ring-shaped island ''(hidden)''|Ru=yes|Sa=yes|E=yes|display={{DL|Vitamin|Protein}}}}
Route 128 retains the north-south alignment of Route 127 as it proceeds south past a pair of islands with one Trainer each. The route turns to the southeast as it swerves to avoid the top of the Seafloor Cavern. On the east side of the cavern's surface, Route 128 splits into two paths, the main north-south path and an east-west path leading to the base of Ever Grande.
The main path of Route 128 continues southwest from this junction, passing two more islands and a Trainer before turning to the south and becoming Route 129.
Ever Grande connector
To bypass an island located due east of the path's western terminus, the connector heads to the northeast, then to the southeast before taking on an easterly alignment near a large island playing host to a Fisherman. After passing a Triathlete, the path enters the city limits of Ever Grande a short distance to the east.
Underwater
Most of the western portion of Route 128, including the area around the Seafloor Cavern, contains underwater passages that can be reached using Dive. The entrance to the Seafloor Cavern is, fittingly, on the seafloor near the southern terminus of Route 128. North of the cavern, the underwater passage continues onto the floor of Route 127.
A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here.
A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here.
Trainers with a PokéNav by their names will be registered in the Trainer's Eyes or Match Call function after the first battle, and may have a rematch with the player with higher-level Pokémon.
Trainers with a PokéNav by their names will be registered in the Trainer's Eyes or Match Call function after the first battle, and may have a rematch with the player with higher-level Pokémon.
Trivia
It is possible for Cooltrainer Ruben to walk over the spot where a hidden Heart Scale is before initiating battle with him. This prevents the player from acquiring the item until they leave and re-enter the route, or dive and resurface, which resets his position.