Little Compass RoseCaribbean Compass   April 2019

From Leadlines to Satellites:
Charting the Eastern Caribbean

by Don Street

In March 1957, I bought Iolaire, a 46-foot engineless cutter built in 1905. For the next 40 years I cruised, chartered, explored, and raced her throughout the Eastern Caribbean. In 1995 Iolaire departed to Europe, and I continued sailing on the 28-foot engineless yawl Li’l Iolaire.

The early days were true explorations. There were no guidebooks, and charts were extremely hard to find. Most St. Thomas-based charter skippers were reluctant to beat across Anegada Passage, so Iolaire picked up the charters from sailors who wanted to sail to St. Martin, St. Barts and beyond. Very little information was available on islands east and south of the BVI.
The Nicholson charter fleet, almost all 65 feet and longer — boats that were in those days considered luxurious compared to the 45-footers in the St. Thomas fleet — didn’t much like beating to windward either. They mostly stuck to a run between English Harbour, Antigua and St. George’s, Grenada. Iolaire was the only charter boat that regularly cruised the entire Lesser Antilles.
My instincts led me to explore “off the beaten track” areas such as the south and east coasts of Grenada and the east coast of Martinique. I worked out ranges/transits that would allow sailors to thread their way through the unbuoyed, unlit Grenadines.
Leadlines and Sounding Poles

Often I would remove my small Wilfred O White dome-shaped compass from Iolaire and take it, along with a lead line and notebook, in the dinghy powered by an ever-unfaithful Seagull. When the Seagull failed, the clinker dinghy rowed beautifully, easily propelled by a pair of light, nine-foot oars. The oars were dual purpose: used for propulsion when the Seagull failed, and as sounding poles in shoal water when the Seagull was running. When running under Seagull power, steering with the tiller extension between my legs, I learned to toss the lead far enough ahead to obtain soundings while underway.
I also stood on Iolaire’s lower spreaders, eyeballing channels through reefs. The year we spent exploring Antigua’s North Sound and Barbuda, I spent a lot of time up there. Soon, I developed a very sore right elbow. The pain did not go away so I finally went to a doctor. The diagnosis, tennis elbow. But I pointed out to the doctor I had never held a tennis racket in my life — I had spreader elbow!

The Trouble with the Old Charts
I eventually accumulated about 150 US, British and French charts, but I was unhappy with some of their accuracy. For example, when I laid out the transit/range that I always used for the south entrance to the Tobago Cays on the BA chart of the Grenadines, it went right over a reef! Obviously the range/transit was correct, the BA chart wrong.
When those charts were made, when considering areas to be covered and the borders of the charts, little thought was given by the cartographer to the sailor using the chart. The top edge of the old BA chart of the Grenadines ended one mile south of West Cay, Bequia, so I glued on a piece of paper with an X representing the lat and long of West Cay. Thus I could lay a course off from Glossy Hill, Canouan to West Cay. Similarly, the US chart of the Virgin Islands cut Gorda Sound in half. For information on Virgin Gorda, Necker Island and Anegada, you had to find — with difficulty — the British chart of the BVI, a chart based on survey work done in the 1870s. This chart ended at the west end of Great Thatch, so only showed the eastern end of St. John.
Both the US and British would produce a chart of an island and a separate chart for its main harbour. Imray, as standard practice, would do a general chart of an island and then put in detailed insets for harbors and important coves.
At the time, to cover Puerto Rico to Trinidad, the US produced 65 charts, the BA 37, France (only covering French islands) 25. Other than the French charts, and a few US and Spanish Virgin Islands charts updated by the US Navy in WWII, the US and the BA charts dated from surveys of the 1870s and had never been updated or corrected. The British chart of St. Thomas Harbor in 1979 showed Ballast Island off Frenchtown, but Ballast Island had been dredged out by the US Navy in 1917!

Could We Do Better?
In 1979, at the London Boat Show, I approached Sanford, a British firm that privately printed charts in competition with the British Admiralty. I proposed to them that they make an arrangement with me to supply them with the information and they make, publish and distribute charts of the Eastern Caribbean. They turned me down flat.
But right next to them was the booth of Imray, another British firm that privately printed charts. Imray is actually an amalgamation of four old chart and guide companies, Imray, Laurie, Norie and Wilson, and traces its history back to the late 17th century. I introduced myself to Tom Wilson and pointed out that until I wrote my own, the guidebook I used in the Caribbean was a Norie and Wilson Sailing Directions to the West Indies, published in 1867. I started to tell him of my guides to give him a sales pitch; he said he knew of my guides. I proposed privately printed charts to the Eastern Caribbean, myself providing the information to update and correct the existing charts and lay them out in a fashion that would be suitable to the yachting sailor.
Tom immediately said, “I like the idea. In the late 18th and early 19th century we produced charts of the Caribbean and Bahamas. We sold the charts and the rights to them to the British Admiralty in the 1830s. It would be interesting to again do charts of the area. Make up a proposed agreement and we will hassle it out.”
I sat down and started to work laying out the proposed Imray Iolaire charts for the Caribbean. Imray and I achieved complete and up-to-date coverage from Puerto Rico to Grenada with only 37 charts.

Adjusting Our Sails
The charts were an immediate success, but with one problem. In spray or damp conditions the paper dissolved with extreme rapidity. I asked Tom Wilson why did Imray not use the same paper as did the British Admiralty? Tom replied, “The minimum order is 16 tons — more paper than Imray could store or use!”
In the late 1980s we were approached by a US company that was printing Bahamian and Puerto Rican charts on waterproof paper. They wanted Imray to sell them the rights to our Eastern Caribbean charts so they could print them. After Willie Wilson and I discussed their proposal, we turned them down. The following year, when I turned them down again, they said, “You must sell out to us or we will drive you out of business”. It was a tough search, but by the early 1990s Willie finally managed to find a waterproof paper on which charts could be printed, so all was well.

But, also in the early 1990s, NV charts showed up in the Caribbean. We had a serious problem on our hands: our best customer was the Moorings, and NV charts were sold through a company owned by the then-managers of the Moorings’ Caribbean fleets. We had to do something to convince them to stick with Imray Iolaire charts. The machine that printed the charts was capable of printing on both sides at the same time. Willie asked me to pull tidal, current, interisland sailing and harbour piloting directions from my guides, and rewrite and reorganize the material so the information could be printed on the backs of the charts, making the Imray Iolaire charts a chart and guide in one. It was time-consuming work but it was worth the effort. The Moorings stuck with Imray Iolaire charts.

Sadly, the big printing machine that printed on both sides of a chart expired recently. Now Imray Iolaire charts are printed on one side only, but the additional information that was on the reverse is still available. The main points are in a booklet that comes with the chart. Information that will not fit in the booklet is found at This can be printed out as a pdf (whether you own the chart or not).

Puerto Rico and Vieques
In the ’80s we started exploring the Spanish Virgins and the east, south and west coasts of Puerto Rico — it was at times again real exploring. We had the latest NOAA charts but we discovered that all the Spanish Virgin and Puerto Rican charts were based on US Navy surveys done from 1902 to 1912. Except for around major harbors, no corrections or resurvey work had been done. While visiting NOAA head office in Washington, DC, I also discovered a detailed unpublished survey of the southwest corner of  Puerto Rico. This we used to make a detailed chart of the La Paguera area, a great cruising ground with more anchorages than you can count.

While exploring in Vieques, a fortuitous meeting in a bar with a submariner resulted in a photostat of the restricted DMA chart of eastern Vieques. The gunnery range was then still active but yachts could visit the area as long as the red flag was not flying from the bombproof observation post. The only detailed chart of the wonderful harbors on the north and south sides of the eastern end of Vieques are found on Imray Iolaire A 131. On the north side of Ensenada Honda two deep creeks go into the mangroves far enough to offer hurricane shelter to a score of boats.
Getting Ahead with WGS 84
When the satellite system became fully operational, all charts and maps had to be recalibrated to WGS 84 (the World Geodetic System established in 1984, comprising a standard coordinate system for the Earth). How to do this as a private company when all the government hydrographic offices worldwide were having trouble doing the job? I started thinking: airplanes navigate completely by GPS; how do they find the airports? I learned that NOAA (the US National Oceanic and Atmospheric Administration) had produced a book that gave the GPS latitude and longitude of the centreline of every airport in North and South America.
So I fed Imray’s Alan Wilkenson the information on the centrelines of the runways that showed on the charts of the islands. He was then able to record on each chart that the GPS position should be moved accordingly when plotting GPS positions. That operation was difficult to do, so I simplified it. Using Alan’s information, I worked out the direction in degrees and distance in yards that a GPS position had to be moved when plotting GPS positions on charts. I also discovered that the BA had corrected some BA charts, but not all; same for the French and the US. We used the BA, French and US information to cross-check Alan’s calculations. Alan, and I were proud of the fact that we had worked out the offset on every Imray Iolaire chart before the various government hydrographic offices had done so.
Alan then started repositioning the charts as they came up for reprinting so that all Imray Iolaire charts were redone to WGS 84 before the government charts were redone. All this work was well worth it as Garmin, Navionics, Jeppesen, C-Map and other electronic chart companies pay Imray a royalty for use of Imray Iolaire information to keep their charts up to date, too.

We can only keep Imray Iolaire charts truly up to date if sailors inform us of errors in the charts owing to changes — such as new marinas, docks, breakwaters or dredging — that they feel should be included in an existing chart or shown in chart corrections at Send information to me at [email protected]

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