USS Santa Ana
The fictional USS Santa Ana was one of two runabouts detached to the [USS Khai Tam (ficticious vessel)|USS Khai Tam]] when she set out on her maiden voyage. The Danube-class runabouts gave extra reach to the Khai Tam's sphere of influence. It is the Starfleet tradition to name ships of the class for Rivers, in this case the Santa Ana River in Southern California on Earth.
Origin
The Santa Ana River ran straight through Anaheim, CA where Kevin McNulty grew up. In fact, Anaheim is German for "home by the river." When developing ideas for the Technical Manual, Kevin and Editor Colin Toenjes decided to name each of the two runabouts after a river by where they grew up. Kevin's pick of the Santa Ana was an easy choice.
Usage
It became common after that to start referring to Kevin's car as the Santa Ana and Colin's as the Kaskaskia, especially on away missions when both would be in caravan. When Colin left, he said that he was taking the Kaskaskia with him literally and figuratively. From that day, the ficticious Khai Tam never again embarked the Kaskaskia. The replacement runabout turned out to be the Appalachacola, though no one's sure if Kevin actually told anyone that.