Map Implementation Question (Pathing, sort of)

[Arideth]

OK so here's what I'm looking to do:

In my game, there will be a world map, and the player will be sailing around on it.

I need to calculate the shortest path to his destination.

Now, I've read up on A* pathing algorithms and I have a good idea of how to do the actual pathing calculations.

The place where I have concern is as follows...

Is there any way for me to determine what is land, what is shallow sea, and what is deep sea without handcoding the value of every single X and Y in my grid?

My map is a 400x300 pixel area. I'm open to any suggestions. I'm really stalling here at the idea of hand entering 120,000 values.

Thanks for your time.

[bauerr]

I'm also a newbie here, so maybe there are better solutions:

Two days ago I asked about
making a 2d racing game and how to determine if the car has left the track. I got an advice which may fit to your problem.
How about making a second map with only a few colors?
For example: all land colored brown, deep water colored blue,...
You could than read your current position from this 'shadow map' and determine what kind of  underground your actual position has.

Here's the link to my question:

http://www.java-gaming.org/cgi-bin/JGNetForums/YaBB.cgi?board=cluebies;action=display;num=1108479531

Ralf

[Malohkan]

is your map such that color differences denote land type differences?  If so, you could check pixels of your map and compare them to your 3 stores color values to figure out what speed of travel they offer.