Istanbul - transportation from Airport to Cruise Terminal

[GenghisQuan]

It seems like a cab is the ideal method due to the luggage that I would need to schlep around. How to do this without getting scammed? Uber? Airport taxi line? Private transport arrangement through Viator? Costa seems to have a taxi service option available, although I have no idea what it means by "cannot be used at transit ports".

Public transport is out as I land on embarkation day and it seems to take like 1.5 hours to get there, on top of wrangling with luggage on the way.

[Mrs. Claypool]

We booked a private car to pick us up and transport us between the airport and the port and it worked very well.  However, our guide arranged it for us, so I can’t tell you how to contact them directly.  
 

But if you log onto TriipAdvisor, they list quite a few private car companies that will take you between the airport and the cruise port. 
 

of course, booking a private pickup will cost more than hailing a taxi, but I think that the peace of mind is worth it. 
 

[fruitmachine]

We booked with Welcome Pickups (who the contract a local driver/company) to get from the airport to a hotel quite near the port in October.

I couldn't have been more pleased with the experience.  A very reasonable price, a new and spotless Mercedes Vito van, and a helpful driver who arrived bang-on the booked time.