Thanks for all the tips. Taking the ferry the night before and staying in PDC or Cancun is tempting, but it means I'd probably have to check out of my hotel before diving on my last morning, and I'll get off the dive boat in the afternoon with nowhere to shower, change, or dry my gear before packing it up.
I'm leaning towards the cab or private shuttle option. Are there pros and cons to just getting a taxi in PDC vs pre-arranging a private transfer? I imagine the private transfer is a bit more expensive?
I have checked out before diving, had the hotel keep my bags then had the dive op drop me off at Hotel Barracuda. I used their rinse tanks to clean my gear then hung it up to dry while I used their pool to and restrooms. But I have also just checked out of my room in Coz that evening after a shower and a nap before crossing the channel, cost an extra $40 but it makes the morning I fly out more relaxing.
I have never used a private shuttle so I can not comment on that.