An order by the US Coast Guard in American Samoa has restricted the entry and departure of vessels in Pago Pago harbour to day time only.
This is because the radar equipment on both government tug boats is not operating.
Licences of all but one of the pilots have also expired.
The deputy director of ports, Christopher King, says the Coast Guard has restricted the two tugs to operating only between 6am and 6pm.
This has meant that vessels coming into Pago Pago harbour can only arrive and depart during daytime hours.
The radar equipment is due to be repaired by this weekend.