A Toowoomba nurse will spend International Nurses Day this Thursday volunteering on board the world’s largest charity hospital ship, as part of a two-year assignment.

Deb Louden has joined the Africa Mercy at Sierra Leone after spending 10 months as a ward nurse aboard the ship in 2009, when it was docked in the West African nation of Benin.

"I serve as a charge nurse in the wards, watching over patients with doctors and specialty team leaders, guiding nurses and coordinating day volunteer translators," Ms Louden said.

The Africa Mercy is part of global charity Mercy Ships, which has operated hospital ships in developing nations since 1978, providing free health care and community development services to the poor.

Each year, the ship provides more than 7000 free surgeries while volunteer medical and support staff pay their way to the ship.

The Africa Mercy houses a state-of-the-art hospital with six operating theatres, 78 hospital beds and a crew of 450 people and also features a range of off-ship projects from optical and dental to nutrition, community health and mental health.

"There is a huge need in Africa. These are people who are desperate for help and I am blessed to be able to use my hands to provide some of that help," she said.

For more information about Mercy Ships visit www.mercyships.org.au