At the risk of dragging this thread out, several references have been made to using old or built-in charts.
I made an offhand reference to the LNM and needing regular updates in an earlier post. Let me explain. Every week, the CG publishes changes to the charts. There are dozens, if not hundreds, of them in each region. This is the Local Notice to Mariners.
For example, a bridge that I need to pass under this weekend is scheduled for maintenance from Friday night through Wednesday. Because I knew this, I'm leaving Friday instead of Saturday so I'm not trapped above it. Last year, I took the South passage around an island instead of the North. Next week, the LNM included a chart update reporting a rock on the North passage. It was only dumb luck that it wasn't me who "found" that rock. But now I know which way I should go next time.
Buoys are moved, shoaling and wrecks can infringe on the channel, lights are removed, and depths are updated. Construction and marine events can affect your plans. Fish farms and other aquaculture facilities are built where there used to be a passage.
The only way to know this stuff is to keep your charts updated. You can read each week's LNM and mark your paper charts yourself. Or you can download the latest electronic charts before getting underway.
Believe me, I've been burned by using old charts, even in waters I'm familiar with.
I would never rely on built-in charts, second-hand chart chips or old paper charts.
I made an offhand reference to the LNM and needing regular updates in an earlier post. Let me explain. Every week, the CG publishes changes to the charts. There are dozens, if not hundreds, of them in each region. This is the Local Notice to Mariners.
For example, a bridge that I need to pass under this weekend is scheduled for maintenance from Friday night through Wednesday. Because I knew this, I'm leaving Friday instead of Saturday so I'm not trapped above it. Last year, I took the South passage around an island instead of the North. Next week, the LNM included a chart update reporting a rock on the North passage. It was only dumb luck that it wasn't me who "found" that rock. But now I know which way I should go next time.
Buoys are moved, shoaling and wrecks can infringe on the channel, lights are removed, and depths are updated. Construction and marine events can affect your plans. Fish farms and other aquaculture facilities are built where there used to be a passage.
The only way to know this stuff is to keep your charts updated. You can read each week's LNM and mark your paper charts yourself. Or you can download the latest electronic charts before getting underway.
Believe me, I've been burned by using old charts, even in waters I'm familiar with.
I would never rely on built-in charts, second-hand chart chips or old paper charts.
