Can SE charts be trusted?

Shippers and boaters beware: Some waters in Alaska haven't been surveyed for 60 years and NOAA charts are in serious need of updating

Posted: Sunday, March 11, 2001

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Where to get charts

Nautical charts can be purchased directly by mail from the National Ocean Service branch of NOAA or through authorized agents listed in a free catalog available by calling (301) 436-6990 or checking the Web site, More information on NOAAs hydrographic surveys division and its Alaska survey plan can be found at

Compare a waterway to a bathtub filled with water. Place sand, pebbles and rocks at the bottom to represent ocean-floor obstructions, and then add a nail sticking up like a submerged pier.

Without the ability to see beneath the surface, poke a swizzle stick through the water.

"What are the odds you're going to hit on top of that nail?" asks Lt. Cmdr. Don Haines, chief of operations for the hydrographic surveys division of the National Oceanic and Atmospheric Administration in Silver Spring, Md. "Without being able to see down there, it is a hit-or-miss thing."

Whether it's your keel or your keister, no one wants to expose their bottom to a sharp object. The risk increases with outdated information.

The data on more than half of NOAA's nautical charts was acquired more than 60 years ago, when sailors used a lead line - basically a long swizzle stick - to measure ocean depths and contours. Positions were fixed by sextant.

Mariners charting the bottom of waterways took samples hundreds of yards apart and made educated guesses at what lies between the survey points. It's called dead reckoning, an interesting term for a navigational tool used to improve marine safety.

"It's really unbelievable the kind of things they were able to find with lead lines and sextants," said Capt. Nick Perugini, chief of NOAA's marine chart division. "However, there are areas where rocks and boulders are basically undetected because they fell between the lead line soundings."

NOAA is recognized by the International Maritime Organization as the hydrographic authority for the United States. It is responsible for about 1,000 nautical charts, including 240 for Alaska.

The charts are a legal requirement for certain classes of vessels, but most mariners depend on them whether they're recreational boaters or commercial shippers.

Recent advances in technology, such as multi-beam sonar and global positioning systems, make it possible to have full-bottom coverage to improve the accuracy and detail of charts. But NOAA lacks the resources to cover its area of responsibility.

"The situation is grave when you consider our total charting responsibility is out to the 200-mile limit, constituting over 3 million square nautical miles," said Capt. Sam DeBow, chief of NOAA's hydrographic surveys division.

Limited funding has forced NOAA to prioritize by identifying 43,000 square miles of "critical survey areas," defined as waterways with high traffic volume and inadequate charts.

More than half of these critical areas are in Alaska, including many straits, sounds and bays in Southeast.

Alaska: a dynamic water world

Unlike the gradual sandy slopes offshore most of the continental United States, Alaska has a dynamic sea floor. Jagged mountains and rock formations above the water usually extend below the surface.

Even if the charts were accurate at the time of production, they may have become outdated and inaccurate because of storms, tidal currents and geological uplift.

A survey conducted in Prince William Sound after the 1964 Alaska earthquake found one area 20 fathoms, or 120 feet, different than the depth listed on the existing nautical chart.

"We found huge differences mainly due to underwater slides from the earthquake scouring one area and depositing material somewhere else," said Lt. Doug Baird, NOAA's navigation advisor in Alaska. "Areas that were deeper were now much shallower and areas that were shallower were deeper."

This shifting of the sea floor can change the way a vessel goes into a bay or other anchorage.

Retreating glaciers and their moraines are another concern. Some glaciers receded as much as 10 miles between surveys. Areas once covered by ice are now covered with water and there may be uncharted rocks and silt lurking beneath the surface.

"Until you can go in there with equipment to get the bottom topography, you don't know what's there," said Cmdr. John Bingaman, chief of prevention and compliance for the U.S. Coast Guard's marine safety division. "We've asked vessels that carry passengers not to approach closer than a quarter mile (of the glaciers)."


Bob Richards of Thales GeoSolutions Pacific, one of two private contractors working with NOAA in Alaska, understands tourists want that spectacular viewing experience. But he thinks the ships should be more wary.

"A lot of cruise liners are going much closer to these glaciers than I would send my survey boat," Richards said.

The marine pilots who help guide cruise ships and commercial vessels through the sometimes treacherous waters of Alaska work closely with NOAA to identify resurvey projects.

"Accurate charts are vital not only for planning but also for navigating close to shore and in shallow waters," said Hans Antonsen, president of the Southeast Alaska Pilots' Association. "The more accurate the charts, the better we can do our jobs in safely navigating vessels."

While Richards' company helps survey up north, the NOAA research vessel Rainier plies the waters of Southeast. Over the past few years the 231-foot ship has surveyed areas from Tracy Arm 35 miles southwest of Juneau to Russell Fjord 15 miles northeast of Yakutat.

The Rainier plans to return this year to Chatham Strait, Peril Strait, Clarence Strait, Sitka Sound, Kasaan Bay, the Gulf of Esquibel and waters west of Prince of Wales Island.

Common sense, caution and experience

Juneau marine surveyor Jim Sepel believes most boating accidents are caused by pilot error, not chart inaccuracy.

Sepel, who surveys boats for bank loans and insurance purposes, had 11 clients involved in groundings last summer. Only one was due to an uncharted rock off Couverden Point, where Chatham and Icy straits meet.

Sepel, who spent 21 years in the Coast Guard, said navigating in Southeast has always been a challenge.

"People tend to get overconfident and complacent, paying more attention to their fancy GPS color chart plotter rather than to where the 'bleep' you are," he said. "Much of the ocean bottom in the continental U.S. is flat and sandy. When you run aground here, the rock always wins."

"I've known for years that charts can be old, so I'm very conservative in my navigation," he said. "I give myself extra room in shallow areas."

When Turner buys charts, which are available at local marine supply stores, one of the first things he looks at is the date of the survey. He also considers other sources of information. The Coast Guard's weekly Notice to Mariners includes revisions to charts and updates on navigation aids.

Chris Stockard, another member of Juneau's recreational boating community, will do his own charting in areas that lack detailed surveys.

"I'll anchor out in deep water where I know it's safe, then go in with a dinghy and sound where I want to go with a lead line," said Stockard, who has a 43-foot sailboat.

Like most mariners, Stockard said common sense and caution are as important as charts.


Personal experience and local knowledge also help, said Ed Hansen, a member of the Southeast Alaska Fishermen's Alliance.

"I've been on about every square inch of Southeast," Hansen said. "You learn there are rocks that are marked and rocks that are not."

He thinks outdated charts could be more of a problem for sports fishermen new to the area, mariners just getting into boating, and captains and pilots of larger, deep-draft commercial vessels.

The route most traveled

The state ferries try to stay on the track that's "tried, true and proven," said George Capacci, director of the Alaska Marine Highway System.

However, ferries sometimes leave their comfort zone while responding to emergencies outside the main shipping lanes.

"I don't know if it's a tremendous risk, but they still have to be careful because there's always the possibility of uncharted pinnacles, sand bars and rocks," Capacci said. "Look at all the buoys in Southeast Alaska. A lot of them have the names of ships that found those hazards."

Maritime traffic is increasing while ships are getting longer, wider and deeper.

The draft for commercial vessels has doubled in the past 50 years with ships now drawing between 40 and 50 feet of water. Supertankers can draw 60 to 70 feet.

Ships that used to carry 2,000 containers now hold up to 7,000. Barge companies must carry freight across waterways that may not be adequately charted.

"Tug and barge companies know the limitations before they go," Baird said. "They basically make their own charts to augment NOAA charts so they know where to go and where to stay out of. Local knowledge is always better than someone just relying on a chart."

Nevertheless, Antonsen said his Ketchikan-based pilots' association relies on NOAA charts for navigating near glaciers and in shallow waters.

"We're not as concerned with a discrepancy at 250 fathoms than at a river mouth, glacial moraine or area with submarine activity," he said. "A prudent mariner does not rely on any one source of information in navigating, but a chart is a valuable tool."

NOAA depends on organizations such as pilots' associations, port authorities, Coast Guard, U.S. Corps of Engineers, recreational boaters and other mariners to help update their nautical information.

"If we don't get information from those sources, our charts in some cases can be grossly in error," Perugini of NOAA's chart division said.

More technology, less funding

In the 1970s NOAA had 11 vessels to help with surveys, including five in Alaska. It is now down to three ships, including the Rainier.

NOAA's $30 million hydrographic survey budget must be stretched over 3.4 million square nautical miles, an area equal to the total land mass of Alaska, the continental United States and Mexico.

"The 43,000 square miles we're trying to address constitutes 1.3 percent of our total responsibility," DeBow of NOAA's hydrographic surveys division said. "With the resources I have today, it will take 17 more years just to cover an area equivalent to the state of Florida."

Congress is not providing the money NOAA needs, although the Alaska delegation has been supportive.

"Senator (Ted) Stevens was instrumental in getting multi-beam technology in Alaska, so we can do full bottom coverage," Baird said. "It enables us to go in there and mow the lawn."

Antonsen urges mariners to support the surveying efforts of NOAA and its contractors. He said they've been very responsive to the requests of his pilots' association for initiating new survey projects.

"We have a great deal of respect for NOAA and the credibility of its charts," Antonsen said.

Cmdr. Ed Sinclair, chief of aids to navigation for the Coast Guard in Alaska, said mariners must understand that charts can be dated and unreliable.

"We're learning that vessels are using different waterways as years go by," Sinclair said. "We need input on an annual basis to help list priorities and update the aids to navigation aspects of the charts."

"Everybody wins when you keep ships off the rocks," Baird said. "The goods get to where they're going, the vessel owners get to keep their resources, the environment doesn't suffer and people are safer."

Mike Sica can be reached at

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