Around the west of Scotland Portpatrick reception can be difficult to impossible because of topography. On 518 kHz, Malin Head broadcasts Sea Area forecastss for Shannon, Rockall, Malin and Bailey (as well as Irish Coastal and some High Seas Areas).
As noted in the recent RYA Magazine, HMCG has been in negotiation with their Irish colleagues. The result is that, after a little more trialling, Malin Head will use the 490 kHz, national NAVTEX frequency to broadcast UK Inshore Waters forecasts. Areas will be the same as Portpatrick ie Land's End to Cape Wrath, the Minch, Lough Foyle to Carlingford Lough.
The B1 letter will be A so that broadcasts will be every four hours from 0000 UTC. I do not know which slots will be for weather; if anyone knows, please tell me. I assume that the other two slots will be used for weather actuals, again, as in the Portpatrick broadcasts.
Between them, Malin Head and portpatrick are expected to give good reception over much of the area. When around the West of Scotland, it is advisable to select both Portpatrick and Malin Head on both NAVTEX frequencies. That is good advice generally ie select whichever transmitter you want as well as neighbouring stations that you may be able to receive.
The three UK NAVTEX stations will continue to broadcast four Inshore forecasts each day. However, that means that actuals will only bebroadcast at the other two slots. There is simply not enough time to do otherwise at present.
See my NAVTEX page for schedules of most European NAVTEX transmitters.