Rushing along at speeds of up to 24 miles per hour, tidal bores are an unusual, unforgettable sight in Southcental Alaska. A unique combination of hydrology and geography forms these waves. Cook Inlet has a huge tidal range, and it’s the only place in the U.S. where such a bore tide forms. These extreme tides hit the narrow, shallow and gently sloping floor of Turnagain Arm. Rapidly rising tidewaters are forced up, forming a raised front. Depending on conditions, the bore can be up to 6 feet tall.
It takes hours for a wave to travel from the mouth of Turnagain Arm all the way to far end. Imagine one wave stretched out like a wide carpet, unrolling in froth as it sweeps into a basin of water.
The largest bores occur during extreme minus tides with the full and new moon cycles. The bore wave typically shows up after low tide in Anchorage.
You won’t find many surfers on Alaska beaches, but you’ll find an intrepid cadre of locals who surf the Turnagain Arm bore tide. Rather than short, repeated rides, bore tide surfing means riding the wave for miles and miles. You don’t want to miss this wave; failing to catch it as it rolls by can mean a long float back to their starting spot.
The turnouts along the Seward Highway just south of Anchorage are prime places to spot one of these waves.
Bird Point is a good place to watch the bore tide. Plan to arrive about 30 minutes before the predicted arrival. The water will appear calm just before the bore tide’s arrival. Listen for a roaring sound and watch for a series of waves two to three feet apart breaking near the shore or across channels. On a big day, you might hear a roar of water as the wave passes by. If you reach a spot and the water is already rising, move further on; it's already passed by!
Beluga Point, Indian Point and the bridge near 20 Mile River are also good vantage points with a fair amount of parking. Remember, bore tides travel at about 10 to 15 miles per hour, so you might be able to catch up to one you missed by driving farther south.
Several Turnagain Arm sightseeing tours also hold the prospect of bore tide views.
A bore tide can be seen nearly every day somewhere in Turnagain Arm in the hours after low tide in Anchorage. The size depends on the range of the tide, so the most dramatic bore tides occur during days with extreme minus tides.
Patience is key; it can vary up to 30 minutes or more depending on wind speed and direction.