Sandy Hook, NJ - Surfing, waves, swells, clapotis - Brookdale College Ocean Institute, Sandy Hook, NJ - Dave Grant

Sandy Hook Waves
Dave Grant - Sandy Hook, NJ

	As waves move into shallow water (1/2 their wavelength), they begin to drag on the bottom. The bottom contour influences the type of surf. Breakers are classified as plunging, spilling or surging. (Left) Surfers prefer the plunging breaker which occurs when long period swells travel into abruptly shallow areas and reefs (A bottom slope of 3-11 degrees). Learn more about surfing and protecting the beach at www.surfrider.org
(Note: If any of these video clips are not moving, hit your F5 or refresh key or click the start button of the image,) (Right) The swimmer is encountering a hazardous plunging shorebreak as the waves pass into very shallow water at the beach step. He is attempting to swim out to the more gentle spilling breakers passing over the offshore sand bar. (Bottom slope between 3-7 degrees)
	(Left) The surfer is enjoying some gentle spilling breakers which occur over flat bottoms. He is finishing his ride in deeper water on an even gentler part of the wave that will simple surge onto the beach without breaking. (Bottom slope between 7-11 degrees) Check these links for bottom profiles and beach profiles around Sandy Hook.
Most ocean waves are generated by the wind. The speed, duration and fetch determine the size of the waves. A strong offshore wind produces only wavelets at the shore because there is no fetch (distance for the wind to transfer energy to the water). But miles offshore the wavelets will grow to large choppy waves. (Below)
	Looking out to sea you can see the gusts of wind (Cat's paws) as they begin to kick up waves. Note the ship on the horizon. Sailors hate these gusts, preferring steady winds for smooth sailing instead.
	(Left) The same ship off of Sandy Hook is large enough to ignore the chop that has formed over several miles of fetch, but smaller boats might find it dangerous to venture out.
(Right) Some people call it fun. This hardy fisherman is enduring strong winds, sand-blasting and extreme cold to try and catch dinner.
Some peculiar wave behavior. Waves in deeper water do not break, and these are reflecting with harmonic motion (Clapotis) off the bulkhead. (Right) (Below) Reflected waves intersecting each other before breaking are called "Wedges" and can be dangerous at swimming beaches like "The Wedge" in Newport Beach, California.
Like riding in the back of a pick-up truck... "There's no way to do this and look cool." Henry Hudson was our first shipwreck victim at Horseshoe Cove.	These waves are sometimes called "chop-chop" or "cross-chop" by mariners and can be dangerous to small boats entering inlets.

	Shorebreak: A swell breaking on the beach face.

Standing waves. To study waves, we use our award-winning Sandy Hook - and Day At The Beach beach activities.	Join Dave at lunch hour on Sandy Hook and get a daily surf report at the Dave Page.

How old is Sandy Hook?