Survival experts say two skiers who spent nine days lost on a British Columbia mountainside did at least one thing right in their efforts to be rescued -- even if their SOS signals weren't fully investigated by police when they were spotted.

The Quebec couple managed to stamp the rescue symbol into the snow after they got lost skiing near the Kicking Horse ski resort Feb. 15. Gilles Blackburn, 50, survived, but his wife Marie-Josee Fortin, 44, died before they were found.

Brian Jones, manager of Canada West Mountain School in B.C., said stranded adventurers have to make themselves visible after finding shelter.

"Do what these folks did -- make messages, get some signs out on the snow, so if searchers are looking, they will see your tracks. Be creative and these guys were creative," said Jones. "It was obviously a very unfortunate turn of events."

The couple, who police say were not prepared for the backcountry, had checked out of their hotel at the resort near Golden, B.C., and were skiing out of bounds when they got lost. Officials say the two quickly realized they were in over their heads, but couldn't get back to safety.

No one reported them missing for nine days and police did not investigate the area immediately despite the SOS sightings.

Experts such as Jones, who teaches winter survival courses, say one of the most important precautions winter outdoor enthusiasts should take is to tell someone where they are planning to ski and when they expect to return.

"If nobody reports you missing, if nobody knows where you are, or nobody knows that you are actually out there, they're not going to come look for you.

"It's very easy to do. You don't have to file route plans or anything like that."

Jones said an orange garbage bag and a compact shovel can be the best tools to carry into the backcountry. A shovel can help someone who is lost build a snow shelter or dig down to the ground which is always 0 C, he said.

"If you have sub-zero temperatures and high wind, you could freeze very quickly on the surface."

Most people out skiing for the day won't carry around a heavy portable shelter but anyone can throw an orange garbage bag into a backpack, he added. Cutting a hole in the bag turns it into a ready-made raincoat that traps heat and keeps out moisture.

Andrew Pratt, owner of Inside Out Experience in Alberta, said it's best to stay in one place and make oneself visible to potential rescuers.

The SOS signs in the snow were a smart move, Pratt agreed.

"It's just unfortunate that no one checked it out."

Waterproof matches can help.

"There are lots of different ways of signalling once you are out there. Fires and getting smoke going are classic (signals). If they had matches, they probably would have been found in a day because they would have been able to get a good signal fire going."

Matches will also start a fire to keep warm -- a main priority.

Another priority is getting water, Pratt said. People can survive outdoors for about four days without drinking since dehydration exacerbates the cold and makes the body more susceptible to frostbite.

The final consideration is nourishment, Pratt said. High-energy foods are best but people can get some vitamin C from eating spruce bows and tree bark.

The best way to stay safe, though, is to ensure you don't take too many chances in the first place.

"People who go beyond their abilities are the ones who get in trouble."