UBER can drop people off at SJU but if they pick up the Taxi drivers go into a fit and actually get physical.
A Taxi will be around $85 plus luggage to the Puerto del Rey marina.
Allied car rental has a rental base at the marina and it might be more convenient and economical to rent a car at the airport and do your shopping and drop it off at the marina.
In Fajardo they have a Ralphs and an Econo supermarket where you can provision.