While not an official source the Wikipedia page for most train stations in the UK has a section labeled services, which give an overview of the trains from a station. Example for Kyle of Lochalsh: (https://en.m.wikipedia.org/wiki/Kyle_of_Lochalsh_railway_station)

Always be sure to check against an official source before traveling. If your having trouble finding the nearest station you could consider using one of these maps of the network: http://www.nationalrail.co.uk/stations_destinations/maps.aspx

https://www.openrailwaymap.org/

Also, if you know the date you'll be traveling real time trains is capable of showing all departures from a station on a given day, example for Kyle of Lochalsh: http://www.realtimetrains.co.uk/search/advanced/KYL/2018/02/13/0000-2359?stp=WVS&show=pax-calls&order=wtt

You could also consider posting a more specific question with the island you are actually trying to reach.

While not an official source the Wikipedia page for most train stations in the UK has a section labeled services, which give an overview of the trains from a station. Example for Kyle of Lochalsh: (https://en.m.wikipedia.org/wiki/Kyle_of_Lochalsh_railway_station)

Always be sure to check against an official source before traveling. If your having trouble finding the nearest station you could consider using one of these maps of the network: http://www.nationalrail.co.uk/stations_destinations/maps.aspx

https://www.openrailwaymap.org/

Also, if you know the date you'll be traveling real time trains is capable of showing all departures from a station on a given day, example for Kyle of Lochalsh: http://www.realtimetrains.co.uk/search/advanced/KYL/2018/02/13/0000-2359?stp=WVS&show=pax-calls&order=wtt

You could also consider posting a more specific question with the island you are actually trying to reach.