Blueback 581, several times. The first time was in the mid 1990's, soon after is was brought to OMSI here in Portlandia, and the boat still reeked of diesel and cigarette smoke. The TDC was just standing right there in the control room, begging for people to mess with the knobs.
The next time I went, the TDC was entombed behind a thick plexiglass shield. Boo-hoo!