If you want to be hustled and harangued by Senegal, Moroccan and Arab street vendors selling Snyde watches, fake designer handbags and other assorted rubbish then this port is for you. Expect to be disturbed up to five or six times during a meal and have it all repeated by the same people later when having a drink in on of the many bars.
If you don't mind the above then my recommendations are as follows:
Lunch: you won't beat Ocean Cafe. On the ground level overlooking the marina the food here is superb quality and very generous portions reasonably priced. The staff are very welcoming and friendly.
Evening meal: try the Tapas at Hemmingways. Situated on the first level again overlooking the marina. This is not true Spanish tapas but a delicious mixture of different nationalities. Averaging three to four euros per portion, three would probably satisfy most appetites.
If you are looking foe a decent steak take a walk out of the port along the seafront to Sabinillas where you will find an Argentinian steak house El Estrebo. The size of the steaks here are not for the feint hearted.
The port is extremely picturesque and has plenty going for it. I just wish they would do something about the street vendors.