Create a folder directly on your main drive to avoid path issues (e.g., C:\Navigation\Charts\CM93 ).

Select the Charts tab, then the Chart Files sub-tab. Add Directory: Click Add Directory .

CM93_v2/ ├── 00300000.A (chart cell files, named by cell ID) ├── 00300000.B ├── 00300000.C │ ... ├── 01800000.A ├── ED2HEAD.DAT (header/coverage index) ├── ED2CHRT.DAT (chart cell index) └── ED2SEAS.DAT (seamark attribute index)

Extract (unzip) the folder using a program like WinRAR, 7-Zip, or your OS's built-in extractor.

He watched the progress bar as 1.7 GB of data—containing 144 folders with cryptic 8-digit names—streamed onto his drive. Once the download finished, he used a tool like to extract the folder, revealing the telltale that acted as the heartbeat of the dataset. Setting the Course: Installing in OpenCPN With the data ready, Elias launched