The Macro Pirates' ship is an odd craft with paddle wheels and a large fish bowl taking up all the room on the back half of the ship. The steering is on the front of the ship, and a small cabin is located on the front half of the ship. On top of the cabin is a rooftop held by pillars, a fish on top of the roof and a sofa with a high back underneath. The crew's Jolly Roger is on top of the tank. It was only seen briefly in Hatchan's cover story before Hatchan destroyed it.
They first appeared when Hatchan sold Keimi to them in exchange for a map. Hatchan later comes to believe the map they sold him was a fake, and he destroys their ship, beats them up and frees Keimi. As a result, the crew and Hatchan ended up on negative terms.
The Macro Pirates worked for the kidnapping ring leader Duval, near the Sabaody Archipelago, in order to capture Hatchan and Keimi. After Hatchan was freed, they attacked him, but were easily defeated.
Despite the strong feelings against slavery taken by most fishmen, Macro and his group show no objections towards the idea of selling mermaids or other fishmen as slaves. Additionally, they were once members of the Sun Pirates, who hated that kind of behavior among humans.
All the fishmen that make up the crew are freshwater fish.
They are currently the smallest known crew in the series, made up of only three people.