Starship-Integrated Auxiliary Craft
Starship-Integrated Auxiliary Craft are small craft connected directly to the hull of a starship. This is almost invariably to allow a vessel to carry a craft larger than would be practical in its actual shuttle bays. These craft are occasionally found in other settings, as well.
Captain's Yachts
A captain's yacht is a craft set aside for the personal use of a vessel's commander. In nautical history, such a vessel would be used to transport the captain between a ship at anchor and the port. In Starfleet practice, these are used for away missions deemed necessary by the captain, for diplomatic transport missions, and, occasionally, for recreational purposes, as Starfleet recognizes the enormous pressure starship command places on its officers. Strictly speaking, the 'correct' Earth naval parlance would be for captains to have "gigs" and admirals to have yachts, but Starfleet parlance uses the same terminology for both captains and flag officers assigned a vessel of this type.
Galaxy-type Captain's Yacht
Carried aboard Challenger, Cheyenne, Galaxy, Nebula, New Orleans, and Springfield-class starships, the Galaxy-type captain's yacht is a large, elliptical craft intended for short in-system missions or transport from orbit to a planet's surface. This impulse-only craft could sustain a crew of 2-4 and 4-6 passengers for several weeks, but could not conceivably reach another star system. In all of the classes that use it, the captain's yacht is docked in a special bay under the primary hull.
Atmospheric jets along the edge of the saucer provide lift, and and vector thrust from the ventrally mounted impulse engine to sustain level flight; at high speeds, the vessel must operate essentially on its side, perpendicular to the center of gravity of the planet it's flying over. This luxurious vessel is equipped with two staterooms for the captain or a principal guest, along with a smaller bunkroom for any aides, and another sleeping area for the crew. The bridge is located centrally.
In situations where the mothership must be evacuated, the captain's yacht is intended to serve as a command and control hub for the escape pods, as it has sufficient internal volume for emergency medical triage. In a pinch, this craft can also be used as the nexus of a planet-side research camp.
These craft were produced on a 1:1 basis with their motherships, and production ended in 2395 with the launch of the last Nebula-class heavy cruiser. Truly a relic of an era of hope, these unarmed and ungainly craft are very polarizing; some captains consider them to be a powerful symbol of the Federation and a personal trophy for commanding a mid-24th century starship, while others eschew their use completely.
California-type Captain's Yacht
California and Parliament-class starships share a design of yacht which blends characteristics of the Danube-class runabout and the Type-6A shuttlecraft. Decidedly less luxurious than the Galaxy-type, they are more utilitarian while still being used the captain's personal discretion. They are substantially faster than the standard shuttles carried by these vessels, so they are excellent for situations where the commanding officer must be somewhere quickly or for performing important away missions. Yachts are stored in small launch bays on the underside of the saucer section just large enough to accommodate the yacht itself and a small boarding area.
Sovereign-type Captain's Yacht
Luna-type Captain's Skiff
Integrated Runabouts
Integrated runabouts are general purpose craft intended for extended away missions and planetary exploration. They are generally more capable than captain's yachts at these tasks, but are also less luxurious.