I swear by silk and silk blend twinsets (usually by Ann Taylor or Ann Taylor Loft) for travelling. Wear them together and they look fairly dressy (also very handy if you go back and forth between hot and cold temperatures during the day), the tank top goes under other items (e.g. blazers and suits), the cardigan goes over sleeveless and short-sleeve dresses as well as other tops to dress things up a little. In your case, you probably wouldn't wear the two together for your business trip (maybe a bit too fragile to spend time on the docks), but you could wear the tank under a jacket and then switch to the cardigan later.