Manta Ray - Alma Beach, a little north of Jaffa (on the beach, of course)
also fine for brekkie.
A huge fave of mine, not so close to the port though is Marmourek
(Marmurek ? Marmorek ?) on Marmourek st., next to HaBima theatre.
Fresh, Basic, and great Israeli / Arabic salad.
BTW, the old port area is the Humous capital of the world, with about 5-6 different
humous joints. I like Humous Ashkara - its a bit heavy but good and really fun atmosphere (waiters singing about their crazy veggie soup). It's also open 24/7 except weekends. Humous Neto, on Yirmiahu / BenYehuda is also good.
Tickles my jewbone !
Oh, and Stay off the tourist places on BenYehuda strasse and the hotel area. yuuk.