A Yunboro is generally used for heavy lifting, salvaging, construction, attack, and defense. Due to the relatively archaic conditions of Earth, it can be assumed that these machines were either salvaged from the depths of the oceans, or built using old plans recovered from those salvage expeditions.
In comparison to Chamber, these machines are completely outclassed in terms of physical ability, armaments, and functions.
There are several types of Yunboro.
General Purpose: These can be used for a variety of tasks, but are mostly for construction, demolition, and for defense, due to their heavy armor plating. They can be armed with small guns and other projectile weapons.
Diver: These Yunboro are watertight and are specifically-used to search the ocean depths for salvageable materials. They possess maneuvering propellers and ballast tanks to swim underwater, as well as searchlights to scan the murky bottoms. They are also used to catch fish by using large drag nets. Their ability for combat is limited as they are not armed with any weapons and aren't heavily armored. In case of emergency, the Diver Yunboro can jettison its limbs and its body becomes a life pod which can float to the surface.
Lobster: This is a modified Yunboro piloted by the Pirate Queen Yukkage, which makes use of a high-speed skimmer, machine guns, claws, and grappling lines. It is more heavily armored than most Yunboro.
Pirate Crab: These Yunboros are similar to the Diver-types, but they have been modified for amphibious assault on colony ships. They normally sneak up by carrier submarine, then use their grappling cables to board their prey. Individually they aren't that strong but they are able to overwhelm their victims by sheer force of numbers.