From Bulbapedia, the community-driven Pokémon encyclopedia.
Carlos (Japanese: お父さん Ojisan) is a character of the day who appeared in Date Expectations.
Carlos transported Ash and his friends to Pacifidlog Town on his boat. As the boat approached Donto Island, the boat's engine gave out, forcing Carlos to fix it. Worried that he wouldn't have the engine fixed in time, May asked if there was another way of reaching Pacifidlog Town and the final Contest. Carlos informed her that on the other side of the island was a ferry that could transport them to the island.
After getting caught up with a group of Donphan, Ash and the others made it to the other side of the island, but it was too late for the ferry. Luckily, Carlos had repaired his boat, and returned to the island to make sure the kids had gotten on the ferry. When he realized they hadn't, he gladly transported them to Pacifidlog himself.