The skimmer is a fundamentally simple vehicle, a light mag-rail. Skimmers differ from traditional mag-rails in that the machines are more like self propelled barges than retrofitted and scavenged vehicles.
The Patrol Skimmer
Patrol skimmers are light vehicles with low sidewalls and high visibility. The skimmer is typically used in conjunction with police computer networks and wojek police autons. The skimmer is quick, and allows for the normally plodding machines to be quickly delivered to actionable zones. These skimmers are lightly armored, unarmed, and completely slaved to the police control systems.
Variants: Sled Skimmers are light cargo vehicles, typically used in urban areas where something as large as a loader mecha or power loader droid would be unsuitable. Sled skimmers are common outside of arco areas too, where the infrastructure no longer supports wheeled or tracked vehicles. These work horse machines are the most common non-droid piece of equipment in farming, construction, and resource allocation programs.
Junk skimmers are wastelander specials, being made from cut down shells of vehicles fit with magnetic rail systems. The Junk Skimmer stands apart from the vehicles listed in the Mag-rail article, as they are much slower, much more poorly constructed, and likewise, easier to destroy. The most popular vehicles for junk skimmers are the shells of campers, recreational vehicles, trailers, and other hulks. A junk skimmer can be a slow moving residence, a hovering merchantman, or floating tavern.
The UPC Skimmer
During the 20th century, wars were fought with the assistance of river patrol craft, light boats with a few armor plates and gun placements. The UPC is a very similar concept. The Unarmored Personnel Carrier is a relatively high speed craft, with almost no protection, and a few fixed guns. The main purpose of the UPC skimmer is to ferry low vulnerability low speed assets to combat zones. Skimmers are cheaper than a carry-all, and much lower profile, and are very useful for moving heavy units like power armor troopers and combat droids. These units are typically well armored, and often supply the UPC with their firearms, turning basically a sled into a floating firestorm. The UPC skimmer does offer something that the other skimmer models don't, a fixed weapon. UPCs typically have something along the lines of twin 40mm cannons, whirlwinds, pulse lasers, or in the case of Noddite forces, heat beam THASERs.
The Gunship Skimmer
The gunship skimmer is an armored gunship sled. The body has sloped armor, and fixed weapons. The vehicles trade cargo space for the weight of their armor and weapon systems, typically missiles and rockets. The gunships are relatively unpopular as they are generally inferior to non-hover vehicles, modestly armored, and have limited firepower. These units are usually used as armored cavalry, sweeping along flanking lines and being deployed against infantry and low mobility forces.
The Great Limitation
There is one crippling limitation for skimmers, and all mag-rail craft. The mag-rail system is a glaring target for any smart weapon with an EM sensor system. The magnetic repulsor fields generated by mag-rail engines can be spotted miles away, making these types of vehicles glaring targets. Most advanced forces won't actually fire smart munitions against low priority targets like skimmers, but it won't prevent them from dispatching combat drones, ground forces, or going in for close range combat with lasers.