That depends. Are you willing to spend a little time to learn a navigation system with multiple chart sources so you can keep your crew and your boat safe? Check out Don't Lose Your Boat! to see why OpenCPN and multiple chart sources are a safe and smart way to navigate.
We are Bruce & Alene of s/v MIgration: sailors who have been bluewater cruising for over 20 years and over 150,000 combined nautical miles. More about us at svMigration.com.
Yes, please do. However, we ask that you include the Readme file and let other sailors know about TheChartLocker.com. Also, please don't share the links to the files that reside on MediaFire... just share the links that point to TheChartLocker.com. Thanks very much.
Unlike YouTubers, inexperienced or groupie-seeking coaches, and the whole slew of sailors who are destroying the cruising community by monetizing this beautiful experience, we believe one of the most important elements of cruising is helping each other without trying to be famous or make a buck off of other sailors' lack of knowledge.
Three part answer:
1. Mental health. Social media is harming society and our children. It is documented in thousands of articles and research papers too numerous to list here. But here is one place to start learning.
2. The huge social media companies -- Google, Meta, X, TikTok, etc. -- are supporters of horrible political parties and candidates and have demonstrated time and again that they put profit above the health of our society. They value neither ethical nor moral behavior and are willing to lie for financial gain. We don't support them and hope you won't either.
3. We are Californians (a wonderful state), but that also makes us citizens of the United States. As such, we deplore what has happened to the politics of our country and the rise of lying, unscrupulous, and morally-corrupt political players... many of them from the right and exemplified by the current president (as of 2026). This state of affairs started with Facebook allowing lies to proliferate in order to engage users and keep them in echo chambers where beliefs -- whether true or not -- are repeated and reinforced,
Nope. All charts are only as accurate as their source data. The data from these charts comes from various publicly available sources on the internet. There is no way to ensure the accuracy of the source data or to check the millions of square nautical miles that the charts cover. That's why good seamanship demands the use of multiple chart sources and your eyes.
For Mac users, see the FAQ section below.
We use 7-Zip to zip the MBTiles. Some operating systems might not like the way 7-Zip does its job. If you have problems, download 7-Zip (it's free) and use it to unzip.
MBTiles get VERY large as you use closer zoom levels. Keeping the files to a reasonable size is very convenient as we can include an entire country, coastline, or island group in a single file. We've found that zoom 18 gives enough detail to navigate safely and allows us to avoid huge files.
Much of the data used to create sonar charts is crowd-sourced. Do you trust your boat to someone else's depth sounder? And lots of those depth contour lines on the charts are mathematically estimated so the charts can look more accurate than they really are.
Those charts might be somewhat useful for fishing but they really aren't as great as you might think for navigating and anchoring. Besides, they create a lot of clutter on the screen that can make it difficult to see what is really important. More is not always better.
Nope. OpenCPN is open source software. The terms of use of the Apple App store conflict with the GPL, the open source license OpenCPN uses. Basically, Apple does not allow open source software in its app store.
Yes, The iOS app MAP PLUS can import MBTiles. It doesn’t handle zoom levels as seamlessly as OpenCPN (and it’s not nearly as full-featured a navigation application either), but it does allow iPad users to access the charts that Windows, Mac, Android, and Linux users have been enjoying for years. You can find instructions on how to import MBTiles into MAP PLUS here.
The native Mac unzip utility sometimes doesn't like zip files made on a Windows computer using 7-Zip (the compression software we use). If you have problems, we recommend trying a different unzip program like the free Unarchiver.
It depends which flight you are on.
One of its legs is both the same.
The paleontological correspondence is obvious.
If you have to ask...