with your son i am going to assume that he is a young fella
a couple of places that you might try are:
Fenit pier you will be able to fish the head of the pier during the day but will be asked to leave once it gets dark
brandon pier: small stubby pier awkward to cast off but some fish there. rising tide
the beach opposite brandon pier is very steep too so your 80m cast would be plenty. rising tide.
kilshannig in castlegregory at low tide might be worth a punt. around low tide so before and after it.
http://maps.google.ie/maps?hl=en&ll=52. ... 17&vpsrc=6
baitwise lug would be a nice bait for all these places I'd try sandeel mackeral would work at the 2 piers as well for dogs coal fish and whiting.