Don't use it for Mercury, Venus or comets.
And I always make my geosurvey ships commercial, with size 50 engines (partly because I intend to retool and refit to better engines), because that gives them about 65-70 km/s, which is plenty to catch any body.
Fortunately, if you DO catch a body, you will be able to keep up with it and orbit with it as you survey. Waiting ahead of it until the 5 day movement processes, and then dashing up to it works too.