GPS is to be jammed in an area of the north-west Highlands as part of a major military exercise.
The services will be unavailable at times between Tuesday and Thursday during Joint Warrior.
The jamming, focused on an area around Loch Ewe in Wester Ross, is to be done at specific times.
The Royal Navy said the operations would not affect broadband or mobile phone services and was being done as part of war-fighting training.
Details on the timings of the jamming has been provided by the Navy.
Stornoway and Shetland coastguard will issue messages to civilian ships and boats in the area ahead of the start and at the finish of jamming, which would be suspended in an emergency.
A Royal Navy spokeswoman said: "I can confirm that none of the activity associated with Joint Warrior 181 will have an effect on broadband services.
"GPS jamming operations will take place at specific times and in a limited area in the north-west of Scotland.
"Mobile phone signals will not be jammed during Exercise Joint Warrior and contact with emergency services will still be possible."
She added: "GPS jamming is routinely practiced and is an essential part of preparation for real-life operations, enabling our armed forces to prepare for the modern battlefield."
Jamming is routinely done during the staging of Joint Warrior, a major Nato exercise led by the UK.
The GPS denial operations were suspended during a staging of the exercise in October 2011 following complaints from fishermen.
Running until 4 May, the latest Joint Warrior involves more than 11,600 military personnel from 17 nations.