[ooc: Taking a bit of liberty here just to move things along some...]
Based on the expected rate of drift and last known position of the Dvonn, there is only a small area which the ship could be located in now (assuming it is disabled), and thus it takes Tomas and Trelene only a short time to locate the ship using the boats' ladar. Both engineers determine the Dvonn's exact position, and that it is exactly consistent with expectations - she is adrift. Neither of them finds any metallic objects, other than the occasional iron-rich asteroid within 100km of Dvonn, but ladar is so focused a search tool that there hasn't been enough time to definitively state that there isn't a small ship or other metallic object somehwher in that sphere or the are beyond it - figure 20 minutes more, give or take, for that info, if it's desired. Alternatively, either engineer could use the ladar to try to glean specific info about the Dvonn itself, based on the distortion of the beam as it is reflected back: engine temperatre (to determine when the drives were last used), orientation, detect the presence of oxygen or water crystal external to the ship, etc.
Given the range to target and the reported level of power aboard the ship, the passive EMS is only going to start being really useful regarding the Dvonn in about an hour.
A minute after the ladar goes active, both boats' passive sensors detect multiple active EMS sensors trained upon them. One source is coming from the planet; another is considerably closer, and closing, although at it's current speed, it would be several hours before it reached the two boats.