The Channel Island Air Search team has been called out after a may day call was issued this morning.
A report was made to Jersey coastguard at 11pm last night (13th March) by a vessel sailing to Guernsey from Jersey, to arrive at around 00:30.
No mariner came in and no more contact was made.
Guernsey Coastguard then received a mayday call at around 4am today, leading to the decision to put out the air search crew.
Ports of Jersey says its an ongoing incident, but no-one has been reported missing from either island.
Guernsey Coastguard says there's nothing at this stage to link the two incidents (the call to Jersey coastguard and mayday call to Guernsey Coastguard).

Channel Islander abandons Bordeaux as the flames 'arrive at the city's gates'
Man in hospital after serious assault at Havre Des Pas festival
Jersey teen taking on 'Journey of Hope'
No increase in domestic abuse reports in Jersey during World Cup
Nowacki wins Jersey’s first Commonwealth Games medal in 36 years
Commonwealth Games: Nowacki into 100m breaststroke final
Thousands expected at Havre Des Pas Festival this weekend
Channel Islands face 'physical' Poland test