They don't have a shuttle which is surprising as other hotels nearby do
Uber and Lyft drop off and pickup right on the circle drive right in front of the Marriott
I was there recently. The airport information desk directed me to where the 992 but would stop and even helped me with change. Following the Google Map directions, I alighted at Broadway and Front Streets and walked down Front and into the hotel. I did the reverse to go back to the airport. Google maps is well integrated with Sam Diego transit system and had real-time arrival information. Easy-peasy.
I'm not sure about the shuttle, however there is a bus that goes to the airport from downtown. From your Hotel take the green line Santee to Santa Fa Depo there ask the station attended what bus will get you to the air port or call San Diego MTS. Have a safe trip!
I wish they had a shuttle but no.
Uber
Call the reception please
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