Helm ships one chart pack per region rather than one file for the country, and every pack is built from the official NOAA electronic navigational charts for that water. This page is the count: what is actually inside each one.
Across the 18 coastal and Great Lakes regions below that comes to 3,619 NOAA ENC cells, 1,779,050 individual charted soundings, 16,763 charted wrecks and 2,299 NOAA tide prediction stations. Pick your water to see what its own pack carries and what the numbers mean once you are out in it.
| Region | ENC cells | Soundings | Wrecks | Tide stations |
|---|---|---|---|---|
| New England | ||||
| Massachusetts & Boston | 179 | 115,953 | 707 | 100 |
| Maine Coast | 151 | 121,067 | 202 | 118 |
| Northeast | ||||
| Long Island Sound & NY | 234 | 201,800 | 2,836 | 180 |
| New Jersey Shore | 146 | 75,848 | 1,763 | 216 |
| Mid-Atlantic | ||||
| Chesapeake Bay | 237 | 141,077 | 1,673 | 217 |
| Southeast | ||||
| Carolinas & Outer Banks | 268 | 72,982 | 720 | 142 |
| Georgia & Savannah | 91 | 44,839 | 227 | 115 |
| Florida | ||||
| Florida East Coast | 242 | 130,555 | 1,015 | 351 |
| Florida Gulf Coast | 168 | 115,701 | 874 | 211 |
| Gulf | ||||
| Alabama-Mississippi-Louisiana | 357 | 115,671 | 2,447 | 137 |
| Texas Coast | 213 | 74,056 | 1,103 | 79 |
| Florida Panhandle | 107 | 55,980 | 490 | 79 |
| West | ||||
| Puget Sound & PNW | 219 | 103,658 | 457 | 178 |
| San Francisco & NorCal | 112 | 51,821 | 497 | 137 |
| Southern California | 76 | 62,883 | 269 | 39 |
| Great Lakes | ||||
| Lakes Huron & Superior | 372 | 130,063 | 579 | no tide |
| Lake Erie & Ontario | 246 | 89,773 | 427 | no tide |
| Lake Michigan | 201 | 75,323 | 477 | no tide |
Counted layer by layer from the chart packs themselves. The Great Lakes have no meaningful astronomical tide, so no prediction stations are listed for them.
The regions above are the coastal and Great Lakes packs. Inland water is packed separately. The commercial rivers each get their own pack and their own count, on the rivers page, and lake depth is built from state elevation surveys rather than from NOAA charts, which the lake charts by state pages explain.
These counts describe what the chart pack carries, not the state of the water today. Charted data ages, channels shoal and marks move. Keep a lookout and verify locally.
Helm builds one chart pack per region rather than one file for the whole country, so you download the water you actually run. The 18 coastal and Great Lakes packs on this page are built from 3,619 official NOAA electronic navigational chart cells between them.
No. Charts stream while you have a signal. The pack is what keeps charts, routing, depth, tides and the anchor alarm working when the signal goes, which on most of this water is a question of when rather than if.
Every count is taken from the chart pack itself, layer by layer, out of the official NOAA ENC releases the pack is built from. Nothing on these pages is an estimate.
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