How much toothpaste do you use in six months?
David and Diane Masters have been monitoring their usage as they pack for a half-year stint on one of Australia's most wild and remote islands.
The Masters will soon be volunteer caretakers on Maatsuyker Island off the rugged south-west coast of Tasmania.
The pair will have to take with them everything they'll need for those six months — from toilet paper to perishables, flour and linen.
There is a limit on how much they can pack because it will have to be transported as a sling load, suspended underneath the helicopter that drops them off.
Everything they take to the island that isn't consumed will have to come home, including all their rubbish.
Mr Masters, 64, said they had consulted with past caretakers for ration tips.
"Each person who has gone has done a spreadsheet, and then we compare their sheets and talk to them about what they took too much of and not enough of," he told Jane Longhurst on ABC Radio Hobart.
"Most people thought they took too much of things like herbs and spices and not enough chocolate."
In preparation, they have been thinking about their usage of daily necessities, including toilet paper.
"You actually start putting dates on things and testing yourself on how much you use," he said.
While the Masters are away they will celebrate Christmas, New Year's Eve and their wedding anniversary, so six bottles of sparkling wine have been rationed for special occasions.
The spare room at their West Hobart home is filled with large plastic containers which are allowed to weigh 20 kilograms each so the 600-kilogram limit can be carefully measured.
Precious commodities like coffee are stored in one, while others contain books, cameras, art supplies, flour and woolly pyjamas.
They depart in September, with a date to be advised, because the helicopter ride will be weather-dependent.
It may mean Mrs Masters will also mark her birthday on the island.
"We have a window of a couple of weeks; we may get a phone call to say it's on tomorrow," Mr Masters said.
"If they don't think they can land at Maatsuyker they don't go.
"Your departure is at the mercy of the elements."
An island dream
Maatsuyker Island has been on the couple's radar for about 10 years, and both have visited in the past to do short stints of volunteer work for weed eradication and maintenance.
The 10-day working bees have given them some idea of what they are in for.
"It's not luxurious but it's comfortable," Mr Masters said.
Mrs Masters, 62, is a visual artist and her experience living on the island will inspire a series of works.
She has an exhibition planned for September next year to showcase the art from the island.
Maatsuyker's wild and rugged beauty will be front and centre.
"It's just spectacular, it's windswept but it is wooded," she said.
"In late spring and into the summer it's absolutely covered in blossoms."
Mrs Masters is also excited about the island's abundance of native peppers and the prospect of simply taking some "time out".
"As much as I love ABC News 24, I'm very much looking forward to not having that news cycle," she said.
"There will be physical work to be done, but as a visual artist there will be time to think and reflect on what I want to do."
Her current dilemma is that her art supplies weigh 30kg and will have to cut back by 10kg.
"I'm taking Japanese papers so if I want to do any printmaking I can hand print with that," she said.
"I'm taking ply, some lino, drawing materials and pastes.
"I have to decide what I cannot take."
A day's work on the island
The Masters' day will start at 6:00am, when they are required to send weather observations to the Bureau of Meteorology.
"I'm really looking forward to that aspect of living on the island because the weather changes so quickly," Mrs Masters said.
"The moods of the place are just amazing."
Their home is in the head lighthouse keeper's quarters, which is one of three houses on the island.
There's weeds to pull, grass to mow and vegetable gardens to tender.
The couple will bake their own bread and make crackers to save on packaging.
"There are no days off," Mr Masters said.
"But it's a spectacular place. It is a place where you can smell the roses."
The lighthouse, which was first lit in 1891, has been automatic since 1996.
The Masters' only companions will be Australian fur seals and elephant seals, as well as thousands of shearwaters and other creatures who call the island home.
There is no mobile phone reception but there is limited internet access and the couple will have radio contact with Parks and Wildlife services most days.
Winds on the island can get up to 180 kilometres per hour.
The stint ends in March and Mrs Masters said her only fear was that six months won't be long enough.
"I can't wait to get there."ABC