Chart Authorities Oblivious Re: Nonexistent Island Along ‘Thorny Path’

Rediscovering the Lost Port of Christopher Columbus

Peter Swanson Jun 9

An island sank in 1946 as a result of a terrible earthquake. It wasn’t a big island, only 52 acres, but it formed the principal barrier to ocean swells protecting an old coconut port on the Samana Peninsula of the Dominican Republic. The port was first identified by Columbus in 1493 and was considered significant because it could shelter ships on an otherwise inhospitable coast.

The reason old Port Jackson still matters is that Jackson Cay only sank a few feet underwater and thus continues to attenuate waves that would otherwise roil the hundred-plus acre basin, which happens to have good holding. Consider atolls of the South Pacific, whose coral reefs protect an anchorage within.

Port Jackson is no hurricane hole, but its sunken island and fringing reefs do provide a modicum of all-weather protection, most critically from northern swell. And it lies along the “thorny path to windward” that small craft mariners must transit en route from Florida to the lower caribbean.

Too bad generations of cruisers have never known about it. And the reason for that is simple: The chartmakers of the world never took note of Jackson Cay’s demise. Even though it sunk in 1946, Jackson continues to appear on charts today, 79 years later.

If the principal landmark for finding the entrance to a harbor is an island almost the size of the U.S. Capitol grounds—and that island does not present itself—a passing mariner is not likely to trust the safety of vessel and crew to investigate, particularly in an area of numerous breaking reefs.

A quirky gringo author named Bruce Van Sant wrote “A Gentleman’s Guide to Passages South: The Thorny Path to Windward,” which discussed in detail the gnarly nature of Dominican waters. Van Sant told Loose Cannon about the time he put-putted around looking for Port Jackson. Charts and U.S. Navy Sailing Directions placed Port Jackson behind a protective island, but Van Sant didn’t find it nor could anyone else because they needed to identify the island first.

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Local fishermen and tourist excursion captains, who do not use charts to navigate, have no problem accessing the basin and picture-poscard beach because the entrance is actually pretty straightforward, as described in the story linked below.

The Lost-and-Found Dominican Harbor: A Users Manual Peter Swanson   ·   January 5, 2022 Read full story

Once upon a time, charts for the Caribbean were the purview of the U.S. Navy Hydrological Office, which in 1972 was merged with other government mapmakers into the Defense Mapping Agency, which in 1996 became the National Imagery and Mapping Agency, which in 2003 became the National Geospatial-Intelligence Agency. Given enough time, acronyms thus generated may well comprise the entire alphabet.

Loose Cannon was dealing with the NGA, which calls itself the U.S. intelligence community’s go-to agency for processing and analyzing satellite imagery. It is referred to as one of the “Big Five” U.S. intelligence agencies

First I laid out the scenario to NGA spokesman Nancy M. Rapavi and explained why clarity regarding Port Jackson was in the public interest, along with the above image from Google Earth (which may well be NGA product). In this context I sought a general explanation about how NGA updates its charts. Her answer was unhelpful:

The factors that go into determining the need for a new edition of a chart are the following: The accumulation of Notice to Mariner corrections, the nature of the corrections and the age of the chart. The availability and releasability of new sources are also taken into consideration when determining the need for a new edition and include the following: charts with new data, hydrographic surveys and aerial or commercial imagery.

My response was as follows:

I guess what I really need to know is this: How can a significant feature such as Cayo Jackson still be on our charts 70 years after it disappeared under the water? Especially nowadays, when you can use Google Earth, and clearly see by the satellite imagery that it is not there.

I am not picking on NGA in this. British Admiralty Charts also show Cayo Jackson as still existing.

This issue is further complicated by the fact that NGA Publication 147 (En Route) Caribbean Sea Volume 1 of 218 actually makes reference to “Port Jackson” on page 129. Port Jackson is of course the sheltered basin that was once defined by Cayo Jackson (or in English, Jackson Cay.)

There is no Jackson Cay. There has not been a viable port there since 1946. All this is easily checkable. Will NGA now correct its charts and sailing directions?

Crickets…Ghosted by Nancy.

The question of whether NGA, thus informed, will correct the chart has some relevance, not because a few cruisers might benefit, but because the U.S. Navy uses NGA charts, and therefore the Navy must also believe that Jackson Cay is still an island.

According to an former civilian cartography executive that I interviewed, charts are generally updated more frequently for high-traffic or strategic areas. He said Port Jackson’s isolation and decades of disuse before the 1946 earthquake probably best explain the errors.

In the mid-19th Century Port Jackson was considered strategic because a frigate anchored therein could use its guns to cut off land access to all of Samana. At the time, the only way to resupply military forces at strategic Samana Bay on the south side of the Samana peninsula was a path, suitable only for pack animals, that ran behind the length of Jackson Beach.

Draft for a frigate back then was about 20 feet, which the Port Jackson entrance and basin can easily accomodate. Today’s U.S. Navy Littoral Combat Ships draw 13 feet and, though unlikely (at least one hopes), there may come a day when Chinese submarines call at Cuban ports, and LCS vessels (some of which are anti-submarine capable) will need a place to chill next to deep water on the route to Havana.

Arguably, the venerable British Admiralty is even more negligent than NGA in its coverage of Samana waters.

British Admiralty charts also show an island where no island exists, and the Admiralty’s piloting guide to the Caribbean Sea at the time of this writing gave highly specific directions on how to enter non-existent Port Jackson using the non-existent island as a landmark.

Through the good offices of Bluewater Books in Fort Lauderdale, a distributor of Admiralty charts, I sought comment from the United Kingdom Hydrographic Office.

Crickets again…Not even a “cherio, mate.”