The calm of a hospital ship is shattered by the blasting ring of an alarm followed by an urgent announcement:
"Helo crash on deck; all medical emergency personnel report to your duty stations".
Nobody is quite sure exactly what the extent of the incident is, all they know is that they need to be ready for an influx of casualties.
There is no panic, people go about their duties and prepare their areas as first responders grab their gear and move with quiet haste to the scene.
While this is only an exercise, for Australian Army soldier Corporal Mark Lamb this could one day be a reality.
Corporal Lamb is an Advanced Medical Technician from 2 Health Support Company, Gallipoli Barracks in Brisbane.
He is serving aboard the US Naval hospital ship USNS Mercy for Pacific Partnership 16, a four-month humanitarian assistance and disaster relief exercise which this year is visiting Timor Leste, The Philippines, Vietnam, Malaysia and Indonesia.
USNS Mercy is a 69,000 ton floating mega-hospital that boasts over 1000 beds, twelve operating theatres, pre and post-operative suites, full blood and pathology suites, a radiology department, a dental suite, ophthalmology capability and four intensive care units including an isolation unit.
Participating in mass casualty exercises is only a small part of what Corporal Mark Lamb is doing on Pacific Partnership.
His normal medical duties include attending 'sick call', where he can see and triage up to 60 patients a day.
These cases can vary from coughs and colds, fractures and sprains through to more high level issues such as dengue fever, malaria and norovirus.
"We see and triage patients, assessing and treating both acute and emergency situations," he said.
"We take vital signs, administer medications and intravenous therapy and make electrocardiogram assessments.
"The diversity of the issues we see on a daily basis in sick call varies significantly.
"We could have someone come in complaining of headaches through to sprains, sore joints or infectious diseases."
Pacific Partnership has also given Corporal Lamb other opportunities to share his knowledge and expertise through subject matter expertise exchanges and community health engagements.
He is also an active lecturer for the Basic First Responders course, teaching host country and partner nation people on what to do if they are the first responder to a situation that requires some form of medical intervention.
"Going out into the community and working with local people is really rewarding," he said.
"Being able to show them what and how to do things if they are the first responder has been exciting.
"Knowing that what you teach them could save a life is a great feeling."
During some of Mark's downtime he volunteered to help out at the Tuong Lai Specialized School in Vietnam that provides education for special needs students including deaf, mute, hearing impaired, autistic or children with developmental issues.
The school building had a broken gate and badly needed re-painting so when the call for volunteers was made, to go out and work alongside the US Navy Seabee engineers, Corporal Lamb decided to help out.
"Probably the most enjoyable part of Pacific Partnership so far for me was helping out at the school for the deaf children in Vietnam," he said.
"I felt very privileged to be part of the painting team and hope I made a small happy difference to the children's lives."
