The navigation computer needs the NavComp part to work

The navigation computer needs the NavComp part to work is a side quest in Fallout 2.

Detailed walkthrough
In order to sail across the ocean to the Oil Rig, the Poseidon Oil tanker needs fuel and a working navigational computer. This is an assignment composed of two parts, first you need to retrieve the tanker FOB from Navarro and the NavCom parts from a locked locker on the third level of Vault 13. Then comes the hard part - you need to navigate through the monster-filled tanker hold in order to reach the access point to the navigational computer. Once there, use the FOB to gain entry, go up and install the parts.