I'm only aware of two ways to do TRACY Arm. First, is for your ship to arrive in Juneau at 7 a.m. or earlier and stay until at least early evening. Its a 10 hour trip through Adventure Bound leaving at 8 a.m. Second, is on a northbound itinerary that arrives in Juneau at 1-ish. The ship deboards passengers for the TRACY Arm Excursion near the entrance to TRACY Arm and then continues on to Juneau. The excursion visits TRACY Arm and then meets up with the cruise ship back in Juneau.
Others may know if this excursion is possible on certain southbound itineraries out of Juneau. Same idea, but in reverse.
If you get the chance, TRACY Arm is a beautiful excursion.
P.S. Repeat after me: TRACY Arm, not Tracey Arm. Icy STRAIT, not Icy Straight.