Maritime safety: weather and navigation

1. Maritime Safety Information broadcasts

HM Coastguard regularly broadcasts Maritime Safety Information (MSI) by radio. MSI includes:

  • information on wind strength and direction
  • warnings of restricted visibility
  • updates on sea conditions
  • navigational guidance and warnings

MSI broadcasts may be interrupted or delayed due to search and rescue operations.

You must check MSI and other weather and tide information to avoid collisions and accidents at sea. You must also make sure that you understand any navigational guidance or warnings that are broadcast to your ship.

How to receive MSI

MSI is broadcast:

  • by NAVTEX (Navigational telex) out to 270 miles
  • on VHF out to 30 miles
  • on MF out to 150 miles

Read the Maritime and Coastguard Agency (MCA) guide to maritime safety information, which includes information on broadcast frequencies.