2.2K views · 21 reactions | How to READ DEPTH on a chart: The numbers you see on a chart or an electronic chart are the depth which is the average of the lowest tide of the past 19 years. This is called the mean lower low water and is meant to make it as conservative as possible so you do not run aground. #howtoboating #howto #boating #boat #yachting #yacht #chart #driving #depth #travel #gps | How to boating | Facebook