TVMDC is an App that runs on iPhones and iPAD’s.
You can download it from iTunes here…
TVMDC is the instant calculator used to correct a boaters course when navigating a water.
The two main errors involved in navigation, that need to be corrected for, are:
- Compass Errors
- Set & Drift Errors
Compass Errors are those associated with magnetic anomalies that lead a big difference in your compass bearing to a True bearing. We all this a static compass error. It is a fixed error for a certain boats compass at a certain location on the planet, at a specific time. This error will change over the years, as the earth’s Magnetic Pole moves and it will different on different boats due to the varying amount of ferromagnetic metal on a boat. The TVMDC calculator provides for a quick fix – to correct your heading.
Set & Drift Errors
Set and Drift Errors are Dynamic Errors. They have to do with movement through the water. These errors are a result of wind and tide moving a boat in an unintended direction. If you point you boat in one direction, it is not certain that the boat will move in that direction. In addition to moving in the way that you’re heading, the boat will be also moved by winds and tides resulting in a combination of all of these effects: Boat Speed, Wind Speed & Tide Speed. Each vector component having it’s own direction and speed. The TVMDC App will allow you to first, calculate your set and drift error and secondly, use it to allow you to calculate your best course to steer, to get to your intended destination.