It's called a bore tide, but ask anyone who's seen one -- it's far from boring.
Turnagain Arm and Knik Arm are the only places in the United States where tidal bores occur regularly. Experts say Turnagain Arm has daily bore tides, but they are sometimes difficult to spot when the tide changes aren't big.
A bore tide is a breaking wave up to 6 feet high rushing at up to 15 mph with an incoming tide.
A tide table is key to catching a strong bore tide along Turnagain Arm.
First, identify days with large negative values for low tide. Second, find a good vantage point along the Seward Highway, from McHugh Creek to Girdwood. After a low tide in Anchorage, the bore tide should reach Beluga Point 1 1/4 hours later and Bird Point 2 1/4 hours later.
Finally, get to your vantage point at least 30 minutes before the tide should arrive. Wind and tidal range cause variations in time.
Sea gulls often fly along the bore tide looking for small fish, and beluga whales have been seen playing in the wave as it forms.
Cook Inlet's extreme tidal range is partly responsible for the bore tides. Upper Cook Inlet's nearly 39-foot tide is one of the greatest in North America. Nova Scotia's Bay of Fundy has the greatest range.
While waiting for the bore tide, stay off the mud flats that are visible around much of Southcentral Alaska. Rescue personnel warn residents and visitors to keep clear of the mud. The glacial silt can be very sticky, and people have lost their lives in the mud.
Most beaches around Anchorage are covered in the glacial silt, but many of the beaches on the Kenai Peninsula and in Prince William Sound are perfectly safe to stroll on and enjoy.
