Hurricane Lessons Learned

The 2017 hurricane season brought larger and more frequent storms that caused significantly more damage than anyone thought possible. It also brought some hurricane lessons.

The latter days of summer still bring warm temperatures and typically good weather to enjoy being near, on or in the water. But they can also bring great storms in the form of hurricanes. In fact, although the official hurricane season is from June 1st to November 30th, the peak of the season is from mid-August to mid-September, when ocean temperatures are at their highest—fuel for hurricane development. What can we learn from the hurricane lessons of 2017?

What’s in a name?

A hurricane is a type of tropical cyclone, i.e., a low-pressure area that only forms over warm water. It contains bands of showers and thunderstorms that rotate counterclockwise around a center (the eye) and extend outward for as much as several hundred miles.

Actually, the term “hurricane” indicates the strength of the storm. Hurricanes have sustained winds greater than 73 mph. Systems with winds between 39 and 73 mph are classified as tropical storms, and those with winds less than 39 mph are called tropical depressions. Hurricanes themselves are also ranked in terms of strength according to the Saffir-Simpson Scale—categories of one at the low end to five at the high end with sustained winds exceeding 156 mph. (Gusts can approach 200 mph.)

The greatest threat to ships at sea comes from the strong winds and the high waves they can generate. Stronger and larger storms will produce the highest waves. In fact, measured waves have exceeded 50 feet and, theoretically, a rogue wave in that environment could exceed 100 feet. In those conditions, a boat can easily capsize and sink, and keep in mind that rescue efforts are nearly impossible.

Skip the beach

For beachgoers, even if the storm is far off, swells can make for dangerous surf conditions. As the storm nears, waves become higher and more frequent, and strong rip currents can be expected. Along the coast, the greatest threat comes from the strong winds and, especially, storm-induced high tides. “Storm surge” is an inland rush of water caused by strong onshore winds. High waves on top of this surge can literally smash structures. Storm surge is highest with stronger and larger storms and maximum where the center crosses the coast. Hurricane Katrina produced a storm surge of nearly 28 feet at Pass Christian on the Mississippi Gulf coast, and the surge pushed inland at least six miles.

Even boats at a dock face risks. The risk magnifies with the strength of the storm and the proximity of the eye. Strong winds and high waves can batter a boat against the dock itself, and restraining ropes can break under great stress. A significant storm surge can drive a vessel far inland and as the storm moves by, the wind direction will change by as much as 180 degrees. A more sheltered, inland port is a better alternative.

As you move away from the immediate coast, wind can still do damage. In particular, trees are broken or uprooted, which can take out power lines. That was the case in Puerto Rico with Hurricane Maria. In addition, there is also a significant concern with the heavy rain that can produce inland flooding. Hurricane Harvey, for example, dumped over 60 inches of rain in the Houston, Texas, area last September causing the catastrophic flooding there. If this wasn’t enough, tropical cyclones, when they start affecting land, can generate tornadoes and are most likely to occur in the right front quadrant of the storm. Hurricane Harvey produced 57 tornadoes.

Be in the Know

There is only one official source of hurricane information: The National Hurricane Center (NHC) in Miami, Florida. Media outlets and even private weather companies get their information from the NHC. The Center will send out storm bulletins every six hours or every three hours if the storm is endangering land. The Tropical Cyclone Public Advisory gives a plain language account of the storm, including current strength and location and forecasts for future strength and movement out to five days. This information is also provided in map form. The Forecast Advisory adds marine information for areas predicted to be in the path of 64-, 50-, and 34-knot winds and 12-foot seas.

The NHC will issue specific watches or warnings as needed. Watches mean dangerous conditions are possible within 48 hours and to take necessary precautions. Warnings mean a more definite and immediate threat (within 36 hours); seek shelter or evacuate if ordered. Besides tropical storm or hurricane watches and warnings, a storm surge watch or warning is for “life-threatening inundation from rising water,” and an extreme wind warning is for winds in excess of 114 mph. All of this information is also provided by local National Weather Service (NWS) offices. For marine interests, consult the marine forecasts issued by the NWS.

Flagged as Dangerous

There is a more traditional warning system used at select small boat stations along the coast: the U.S. Coast Guard’s warning display flags. Tropical storm warnings are indicated by a single red flag with a black rectangle in the middle. Hurricane warnings are represented by two of those flags. For more information on Marine Safety during hurricane season, go to nhc.noaa.gov/prepare/marine.php

By Ed Brotak Southern Boating August 2018

Open for Business

The Moorings & Sunsail announce they’re open for business after hurricanes.

The Moorings and Sunsail, two of the most trusted names in yacht chartering, are pleased to announce the grand reopening of their British Virgin Islands charter base on December 9th, 2017, just three months after the Caribbean’s record-breaking hurricane activity.

Over the past few months, BVI staff members exhibited tremendous strength and dedication, working tirelessly to help restore operations in Road Town, Tortola, and they are eager to invite visitors back to this world-famous sailing destination.

The Moorings and Sunsail are also glad to report a combined fleet of more than 100 yachts ready for chartering. Additionally, an investment of $66.5 million will bring new fleet shipments for both brands with over 130 boats scheduled to arrive in the British Virgin Islands in early 2018.

According to Josie Tucci, Vice President of Sales and Marketing, “The road to recovery has not been easy, but we simply couldn’t be more thrilled about reopening our base in the British Virgin Islands, and in such a timely manner. Tucci goes on to say:

“The humanitarian response from customers, partners, and employees following September’s hurricanes was overwhelming, and the tenacity of the local communities has been nothing short of inspiring. We believe it is this heartfelt combination of commitment and resilience that has helped us come back so strong.”

To continue supporting the future of the tourism industry and to assist with long-term hurricane relief efforts, The Moorings and Sunsail recently joined forces to establish the Caribbean Comeback fundraiser. Created in the spirit of uniting sailors everywhere, 100% of all monetary contributions go toward the British Virgin Islands, St. Martin and Puerto Rico employees, delivering supplies that are needed such as generators, gas stoves, and miscellaneous building materials.

Please consider joining The Moorings and Sunsail in this massive effort. Every contribution, no matter the size, is immensely appreciated. To donate or to learn more about this ongoing campaign, please visit CaribbeanComeback.com

To learn more about best-in-class Sail, Power, and all-inclusive Crewed yacht charter vacations in over 20 dazzling destinations across the globe, visit moorings.com and sunsail.com. The world is waiting and new adventure beckons around every corner. Come aboard, embrace the wind and water, and create your own unforgettable passage.

Media Contact:
Leslie Montenegro
Leslie.Montenegro@thlmarine.com
727.614.7376

Eddies in the Ocean

Put a Spin on It! Eddies in the Ocean effect more than just the water.

For many years, oceanic circulations were considered to be fairly simple with a huge spinning gyre in the middle of each ocean that was surrounded by swift-moving
currents along the periphery. With advances in observational capability in the 1960s, the complexity of oceanic circulations became apparent. There were numerous vortices or eddies much smaller than the massive gyres but still significant. With a diameter ranging from 50 to 200 miles or more, they are officially called “mesoscale eddies” or sometimes “rings”. They also can extend downward into the ocean for thousands of feet. These eddies can last from weeks to months or even more than a year. They travel hundreds or even thousands of miles albeit at a slow forward speed of perhaps a half a knot.

Strong western boundary currents like the Gulf Stream are prolific producers of eddies. The Gulf Stream doesn’t flow in a straight line; it has meanders or bends. These meanders can form oxbow-like flows similar to the way that rivers do. These oxbows can become cut off, forming eddies in a process that can take a month or more. The Gulf Stream separates warmer waters to its south and east from cooler waters to the north
and west. Depending on which side they form, these eddies contain either relatively warm or cold water compared to their surroundings. Warm eddies are found to the north and west of the Gulf Stream. They rotate clockwise (anti-cyclonic eddies) and sea level is slightly (6 inches or more) higher within them. Cold eddies are to the south and east of the Gulf Stream. They rotate counterclockwise (cyclonic eddies) and sea level is
slightly lower in them.

These eddies are a critical component of the oceanic environment. On the largest scale, they help move heat or energy. They are part of the ocean-atmosphere system that
transports excess heat from the tropics toward the energy deficient poles. Thus, oceanic eddies affect worldwide ocean temperatures and the atmospheric climate above the water.

With varying concentrations of saltiness (cold eddies are less salty, warm ones more so),
they help transport and balance salinity. Warm-core eddies can actually trap and transport a wide variety of aquatic life within them. But it’s the cold-core eddies that tend to have the greater amount of biological activity. Nutrient-rich bottom waters are pulled up in cold eddies and nourish aquatic ecosystems. The nutrients are then transported by the moving vortex.

There are also smaller eddies in the ocean. These measure 50 miles across or less but can still last for weeks or months. And, recently discovered are even smaller eddies, or “submesoscale vortices”; they measure less than a mile across and are primarily surface features. The idea of having progressively smaller vortices in the ocean is consistent with fluid dynamics theory. It’s these small-scale systems that actually transport energy, etc. which achieves the balance nature is always seeking.

How are eddies detected and tracked? Specialized drifting buoys can be deployed and tracked by satellite GPS technology. Their motion over time will indicate any persistent circulations. Satellites themselves have been constantly monitoring the ocean surface since the 1960s. Infrared thermal imagery will show hot or cold eddies clearly. Sensitive satellite altimeters can also detect small changes in sea level, characteristic of these eddies. Some cold eddies will show up on visible images as green vortices if significant amounts of phytoplankton are present.

Besides the broad-scale effects described above, oceanic eddies can have a direct impact on man’s activities. Certainly, nutrient-rich eddies teaming with aquatic life will attract fishing interests. The effects of eddies on current flow and sea level height can impact the operations of offshore energy production sites. The Gulf of Mexico is a prime example of its numerous offshore oil rigs (and soon, wind farms). The Loop Current is the clockwise flow of warm water that dominates the Gulf. It spawns a multitude of eddies, some of which can produce exceptionally strong currents of 3 to 4 knots. Drilling operations would have to be halted if these conditions are encountered. Horizon Marine, an oceanographic services company whose main clients are from the offshore energy industry, keeps track of these eddies. This includes detection, forecasting, and cataloging. They even name the eddies!

And, of course, the impact of eddies on current direction and speed can affect navigation. Forward speed can be hastened or slowed by a few knots. This will affect the timing of operations and fuel usage. Knowledge of eddy circulations that may be encountered can help in planning the most efficient route. Yacht racers even use this information in planning their strategy.

There is also a theory that ties warm-core eddies and hurricane intensification. Tropical cyclones get their energy from warm water. It makes sense then, that if a tropical
cyclone moves over a warm eddy, it would intensify. And keep in mind that eddies have considerable vertical depth; they are deep pools of warm water or “high ocean heat content” as it is known. It appears that Hurricane Harvey moved over such an eddy on Friday, August 26th. It intensified into a major Category 4 hurricane before moving
ashore and devastating sections of the Texas coast before bringing the unprecedented flooding to Houston.

By Ed Brotak, Southern Boating Magazine December 2017

PHOTO: U.S. ARMY/ 1ST LT. ZACHARY WEST

Hurricane Matthew Updates, Snake Cay and other Bahamian Updates

On October 6^th and 7^th, 2016, Hurricane Matthew roared northward through the central Bahamas leaving a trail of damage behind.

The storm was at Category 4 strength for much of that time, with wind speeds upwards of 150 mph near the eye. Thankfully, no lives were lost, although some areas suffered extreme damage to homes and businesses. Recovery and rebuilding efforts began immediately as relief poured in from local and U.S. sources. The worst impacts were in Nassau and New Providence Island, Andros, and Grand Bahama’s West End southern shore. We surveyed a number of sources within the Bahamian boating community to get an idea of the impact on marine infrastructure, particularly the marinas. Fortunately, damage on the water side was generally modest and repairs are moving quickly at press time. Bimini, Great Abaco and the Sea of Abaco, Exumas, and the Out Islands of Long, Cat and Eleuthera are in great shape and should not present any problems. The southeast Bahamas took a close brush from Matthew early but are ready for transients.

Nassau and the rest of New Providence was hit hard, but the marinas are all back in operation and receiving transient boats. The small communities on Andros and West End, Grand Bahama, took the brunt of the storm and will likely be the last to come fully online. At this writing, nearly all of the marinas in these areas are up and running, with a few limitations. But even where the marinas escaped relatively unharmed, nearby businesses and the residences of employees may have sustained damage, so supplies and services may still be limited. We suggest you call ahead to ensure you will find what you need. Bahamians are tough, resourceful and are working hard to restore their own lives. More than likely, by the time you read this they will be ready and anxious to welcome you to their beautiful country.

Snake Cay

In the highly developed area around the Sea of Abaco, there is an oasis of natural quiet that is easily accessible but still seems an ocean away from the resorts of the nearby cays. Snake Cay, about six nautical miles south of Marsh Harbor and Elbow Cay in the Sea of Abaco, is just off the eastern shore of Great Abaco Island. It is uninhabited except for the ruins of development long since abandoned. Exploring ashore is an eerie experience. A major paper company once centered their Abaco lumbering operation here, and you can see the decaying commercial dock and remains of the land-side facilities.

Learning to play the saw, Green Turtle Cay

Island Roots Heritage Festival, Green Turtle Cay

In settled weather, you can anchor on the north side of the easternmost hook of the cay. Holding is a bit suspect, with a thin layer of sand over marl. Set your anchor well and check the set by swimming the anchor. If strong winds are forecast, it is best to move on.

The real reason to visit here is the wonderful dinghy expedition possible from here to the south. Rounding the easterly hook of Snake Cay, turn west and proceed westerly in the deep water channel between Snake and Deep Sea Cays, then turn south on the west side of Deep Sea Cay. From here, you can run south for miles, with a line of small, uninhabited cays to your east and Great Abaco to the west. Depths are generally 1 to 3 feet. Proceed slowly and you are sure to see many turtles, starfish and other marine life in the shallows. The main island is largely free of development, although you will see some intriguing ruins here, too. This is beautiful, unspoiled Bahamas, much as it “used to be”, yet close to some of the most developed parts of the islands.

Island Roots Heritage Festival

Green Turtle Cay hosts the Annual Island Roots Heritage Festival in early May in the village of New Plymouth. Founded in the late 1700s, New Plymouth was originally rooted in the traditions of American Loyalists who fled the newly independent United States after the revolution. But the hardships of agriculture in the islands eventually led many to flee back to the U.S., particularly to Key West, where they were instrumental in the early development of that community. These ties continue today between the sister cities.

The Roots Festival was first held in 1977 on both islands to celebrate their ties and revived on Green Turtle in 2004. Now held annually, the festival runs this year from May 19-21. The festivities include local foods served on the festival site, a Junkanoo Rush, children’s activities including a Maypole, and performances by the Royal Bahamian Defense Force Marching Band and local bands. This is an authentic Bahamian experience well worth a visit.

Navigation Update

Little is yet reported in the aftermath of Hurricane Matthew, but it is safe to assume that some navigation aids and channels have been affected by the storm. Palm Cay reports some marks off station, but repairs will be quickly completed. Other marina channels will likely be similar. The few government marks will probably receive little attention from the authorities in the short term as the focus remains on land-side recovery efforts. As always in The Bahamas, stay vigilant and travel slowly, carefully and in good conditions.

By Rex Noel, Southern Boating Magazine January 2017