From Destinypedia, the Destiny wiki
Launched from much larger vessels such as Ketches, the Skiff is capable of rapidly deploying infantry and armor, such as the Fallen Walker, into combat zones. They do, however, have armament in the form of twin plasma cannons (which deal Arc damage) and bouncing mines, and as such is used as temporary air support while offloading troops and vehicles. The cannons fire powerful explosive rounds that deal heavy splash damage and the mines can block off certain areas. However, it is possible shoot off the cannons with enough fire, thus limiting the Skiff's firepower.
Skiffs are commonly seen sending reinforcements to Fallen-controlled territories, but will also deploy in force into combat zones, such as during Public Events like mining Glimmer or retrieving a Warsat.
List of appearances