Yes they realy look like halfbeaks but the halfbeaks I know from the local pet-store are freshwater-fishes and the ones on the picture are saltwater fishes. These ones are also a lot larger ( half a meter in length I guess ).
marine halfbeaks are generally pretty large, the freshwater ones are all little tiddlers (and the freshwater ones are all tropical whereas there are even marine halfbeaks in New Zealand). I can't tell if the upper jaw is short or not, but otherwise halfbeak looks good for them. For ID, if you can find some pictures online, these ones appear to have a red stripe on the upper and lower part of the tail, and a red dorsal fin, and this might be diagnostic?
These are needlefish (Belonidae), but members of this family are often difficult to ID to species even with perfect underwater views. Identification to exact species based on this photo is certainly well beyond my capabilities, but based on location either Ablennes sp., Platybelone sp., Strongylura sp. or Tylosurus sp.
