Ch 06 (156.300) Boat to boat communications
Ch 10 (156.500) Helicopter / tug operations
Ch 12 (156.600) Port operations (VTS)
Ch 14 (156.700) Harbour operations
Ch 16 (156.800) Calling and distress calls (lifeboat & Coast Guard helicopter)
Ch 37 (157.850) Yacht club/Marina operations
Ch 04 (160.800) Galway Coast Guard radio. Boats transmit on 156.200
Galway Coast Guard radio is operated from the Marine Rescue Sub Centre (MRSC) located at Valentia. Weather reports daily at 01.03, 04.03, 07.03, 10.03, 13.03...and so on. You're bound to hear boats reporting in before they set off on a trip with their boat details, # people on board and their trip details.
http://www.dttas.ie/upload/IRCG_VHF_Network.gif
Committee/Marshall boats usually operate anywhere between Ch 68 and Ch 77 so what I'd suggest to do is program the high channels and just scan. You're bound to pick up something.
On a marine VHF radio set, Channel numbers go from 01 - 28 & 66 - 88. Channels in between are a mix of "private" channels which are manually programmed and for AIS/DSC use. Lifeboats use Ch 31 (156.550) for chatter between themselves.