Finding the Sweet Spot
I’ve been researching how waves are formed in order to create, and by July present, a narrated video explanation for visitors to the new Oceans Institute of the Montauk Lighthouse Museum. We hope to open the doors by the Fourth of July.
Waves, their sound, size, and great variety of shapes, are fascinating. They easily hypnotize us, lull us to sleep, scare us — or thrill us if we’re surfers — and make us sick when what our inner ear senses doesn’t agree with what our eyes perceive.
Reading about the physics of waves has been interesting (and challenging) for me, having had a more intimate and immediate relationship with them as a surfer, sailor, and shipmate on various blue-water vessels over the years. I have bodysurfed and ridden waves big and small on surfboards of all shapes and sizes. I have sailed and fished aboard a great variety of O.P.B.s, otherwise known as Other People’s Boats, whose maintenance and expense was blessedly not my own.
Three out of all these vessels stand out (in no particular order) because of how they were able to find the sweet spots in waves, a function of their designers’ almost mystical mix of intuition and experience at sea.
The first favorite “vessel” is my 8-foot-9 surfboard with a three-fin “thruster” arrangement that Billy Hamilton, its shaper, named the “missing link,” a cross between a longboard designed for riding small to medium-size waves and a “gun” designed for reasonably large waves.
I bought the Link secondhand from a shop in the town of Hanalei on the island of Kauai. Jeff Hakman, the surfer for whom it was custom made for a surf trip to Fiji, had traded it in. With me on board, it has tasted waves in Hawaii, the Caribbean, South Africa, Indonesia, and, of course, Montauk. Billy Hamilton is a surfer who built his knowledge of how waves break into the board’s design so that it actually seeks a wave’s sweet spot, or “trim.” A few years ago, I told Billy over Mai Tais in a Waikiki watering hole how much I loved the Link. I told him I planned to retire it to a place of honor on one of the walls in my home. He said, “Oh no, good surfboards are like ’55 Chevys. You have to ride ’em till they fall apart.”
The second vessel was Capt. Frank Mundus’s shark-fishing charter boat, Cricket II. I fished on Cricket a number of times, including a three-day trip to the Dumping Grounds (the government dumped tons of munitions there) in open ocean well east of Montauk. On that trip, Cricket steamed into a storm that generated swells in the 10-to-12-foot range. Cricket was built by a fisherman after the low-profile, beamy hull design popular in the Chesapeake Bay. Frank told me he tweaked the design according to what he imagined it needed to remain peaceful on a heaving sea. He nailed it.
I became aware of Cricket’s balance as Captain Mundus cooked dinner in a pressure cooker he’d positioned below deck, set right in the center of boat. The cooker did not move. It and those of us sitting around it might as well have been sitting on flat ground, while at the same time we looked up out of the companionway and through the portholes at waves towering over Cricket as she slid over their peaks and back down into the troughs between them. Even her back deck was peaceful. Cricket was built to work with the sea, not against her, to find the sweet spot among her waves.
The third vessel designed to find the sweet spot was the United States Coast Guard Academy’s three-masted barque-rigged training ship. She was built of Krupp steel in 1936 as a trainer for Germany’s Kriegsmarine. Measuring nearly 300 feet stem to stern, Eagle was designed after the steel square-rigged ships that carried bulk cargo such as grain and guano to and from Europe by way of Cape Horn to the west coast of Chile and even as far as Australia. They were seaworthy and efficient, and powered entirely by wind.
Sailors know, and power-boaters wonder, “What’s the big deal” about sailboats. The big deal is the sense of — how to describe it? — well-being, comfort, at-oneness with the sea on a boat that moves through the water under a press of sail. Where a powerboat rolls port to starboard as well as stem to stern in heavy seas, a sailing vessel’s side-to-side motion is reduced, steadied by her sails’ leeward press (not so true with the wind directly astern).
Sailboats designed to be “seakindly” make the natural connection to wind, and waves. Some designs are better than others. Eagle was built using a combination of sail, rigging, and hull design centuries in the making. I had the very good fortune of sailing across the Atlantic aboard the barque in the early summer of 1994.
Because of a series of low-pressure systems spinning off the U.S. coast behind us, we sailed under blue skies, all sails braced sharp in 35-to-40-knot winds for nearly half the three-week passage via the Azores. The seas were large, at least 12 feet, probably more. I was one of a few civilians on board. Another was a man retired from the Merchant Marine. We were standing on the bridge watching Eagle’s sharp cutwater slice huge arcs of green wave into the air to leeward.
We stood ooh-ing and wowing on the steep hill that was Eagle’s deck. She was making her hull speed, nearly 17 knots. The retired merchantman said that in all his years at sea, he had never been on a ship that felt so comfortable at that speed under those sea conditions. I figured he meant ships with the same ratio of overall length to wave-size ratio. I can’t imagine a super tanker pays much attention to 12-foot seas. Eagle finds the sweet spot, rides rather than wallows up, over and down the waves she continues to meet nearly 80 years after her christening.
The book I’m reading makes the point that seamen knew about waves by living among them. But only recently have we gotten a handle on the science of it, how wind blowing across the sea’s surface creates a rhythm that matches the shape and power of atmospheric pulses — the expanding bands of a hurricane for instance. Pulses that are translated into a train of sine curves above and below the surface whose rhythm has been translated into very dry equations. I’m trying to find their sweet spot.