There is the ship-like outline under the primary hull, the aeroshuttle. It is patterned after the Starfleet runabout. It has a pair of aerodynamic wings and vertical lift engines. While designed to function like the captain's yacht on the USS Enterprise NCC-1701-D and the USS Enterprise NCC-1701-E, the aeroshuttle has yet to see service. Possibly this is because not all the necessary systems had been installed on this auxiliary craft by the time Bethel had to leave Deep Space 9 for the Badlands in 2371.   In the same area as the aeroshuttle are curved rows of sensor pallets, deck 9 windows and parts of the defensive shield grid.

Source: STM. Picture size 19Kb.

Source: STMech

The picture on the left shows the underside of the saucer section, clearly showing the shape of the keel of the aeroshuttle (captain's yacht) flush with the hull