Vessels over 300 gross tons may be required to render assistance if such assistance does not adversely affect their port schedule.

Only that vessel, regardless of size, closest to a vessel in distress, is required to render assistance.

Every ship is able to perform those communications functions that are essential for the safety of the ship itself and of other ships.

Vessels operating under GMDSS, outside of areas effectively serviced by shoreside authorities, operating in sea areas A2, and A4 may be required to render assistance in distress situations.

An integrated tug barge operating outside of the range of VHF coastal radio stations are not required to render assistance in distress situations.