ANCHORAGE -

From the North Slope to Southeast Alaska, the state's extensive coastline is shared by both commercial industries and recreational visitors. An online tool used by many of them is being expanded this month.

It can be difficult to imagine the extent of Alaska's coastline -- yet there's a way to see almost all of it in great detail.

On New Year’s Eve 2012, the Shell drilling rig Kulluk lost its towline and ran aground on Sitkalidak Island, not far from Kodiak. Before it was even ashore, though, responders to the incident knew a lot about the area it might hit and the potential impact of an oil spill.

That knowledge was thanks to ShoreZone, a coastal habitat mapping program which offers high-resolution images and even video. Unlike many other maps of Alaska, this one has the ability to take you there virtually.

Susan Saupe, director of science and research for the Cook Inlet Regional Citizens Advisory Council, recently used a search for Sitkalidak Island as an example of ShoreZone’s capabilities. Unlike Google Maps, ShoreZone – which was originally developed as an oil spill response tool -- uses images taken at low tide.

“We knew that the Kulluk was adrift here and it was going toward these shorelines,” Saupe said. “They could see exactly what the beach looked like, what they were dealing with, where they could potentially bring in their resources.”

Over the last 13 years, 80 percent of the state's coastline and its habitat has been recorded. While the council started the program, many other partnerships have been made to bring the mapping to where it is today.

“We made it accessible to anyone who has (Internet) access,” Saupe said.

Many Alaskans are doing just that. Beyond the oil and gas industry, those recreating among the cliffs and crags are finding value in knowing the layout before starting a trip.

This month, ShoreZone is expanding to the Yukon-Kuskokwim Delta region. As the available data about Alaska's coastline grows, anyone from oil spill responders to clam diggers can access it all for free.

Next summer, the council is hoping to cover an area of the Alaska Peninsula where several ships have gone aground.