There is the Ponggol Marina where they have Ubin Seafood Restaurant and Choon Seng Seafood Restaurant. There used to be be another Maltilda Restaurant there but closed down a few months ago. Then, you can also go to Vivo City where they have many eateries facing the sea.
There's a nice restaurant by the seas called Beulieu house (dunno how to spell 'beulieu') at Sembawang Park, Tuah road. The food is great, and it's not that expensive. Plus, you get to choose to sit inside or outside. I always sit outside to enjoy the breeze
HX300/ EPL6/ EOS60D/ 17-55mmF2.8IS/ 100mmF2.8Macro/ 135mmF2L/ 70-200mmF4LIS/ 300mmF4LIS
there's a seafood restaurant at SAF yacht club