In an EMERGENCY at sea call the Coastguard on VHF channel 16 on land dial 999 and ask for the Coastguard.
For routine calls, (weather, tide times, passage plans etc), call the following numbers for the Coastguard Rescue Co-ordination Centres
Aberdeen.............. 01224 592334
Belfast................. 028 9146 3933
Brixham................ 01803 882704
Clyde................... 01475 729988
Dover................... 01304 210008
Falmouth.............. 01326 317575
Forth.................... 01333 450666
Holyhead.............. 01407 762051
Humber................. 01262 672317
Liverpool............... 0151 931 3341
London................. 020 8312 7380
Milford Haven........ 01646 690909
Portland................01305 760439
Shetland ............. 01595 692976
Solent.................. 023 9255 2100
Stornoway............ 01851 702013
Swansea...............01792 366534
Thames................ 01255 675518
Yarmouth.............. 01493 851338
Also see the MCA (Maritime & Coastguard Agency) website
www.mcga.gov.uk