Well, the see in the map you've attached is probably painted with watercolours, so brush on paper. If you want to simulate that, you will need a watercolour paper or wash texture, maybe an aged paper texture and make some use of the mask feature in a program like photoshop to apply that to a pale blue fill.
And happy new year to you too!
Thanks for info. hope to get some more answers
You want to isolate the blue layer and then stack some cloud layers on top of it. Play with textures and grunge effects if you want the sense of watercolours.
FYI. You will get far more out of the process if you start with a tutorial, accomplish it, and then learn to adapt it. Requesting a tutorial for a chosen picture is sort of like asking people to come over to your house to do it for you. Start with the help that is offered and you will have less ambiguous questions that are easier (and more likely) to answer.
Dollhouse Syndrome = The temptation to turn a map into a picture, obscuring the goal of the image with the appeal of cute, or simply available, parts. Maps have clarity through simplification.
It's a little difficult to see exactly what's going on in that image due to the jpeg compression artifacts, but here's a little something I whipped up in a few minutes in Photoshop. Use the eyedropper to pick the brighest cyan as the foreground, swap the foreground and background (x), then use the eyedropper to pick the darkest sea color. Make a layer, filter > render > clouds. Adjust the foreground color to be slightly darker. Make a new layer. I loaded up the Dry Media brushes and used the very last one as the basis for a grunge brush. Open the Brushes palette (F5). I increased the scattering a bit and in the Dual Brush, I increased the spacing, so I had a nice kind of swirly-speckly brush. You might also want to push the exposure jitter in other dynamics all the way up. I didn't do it here, but now I'm thinking it would have been a good idea.
On the layer you just made, make some strokes with the grunge brush. Not too dense, but give the canvas some nice coverage with it. Adjust that layer's opacity to taste.
For the landform, I used the Pen tool to make a path in the shape of the island. I should have smoothed out that point at the bottom, but this was just a quick tutorial. New layer, eyedropper the land color, fill the path with the foreground color. I then went into the Layer Effects and turned on Inner Glow. Change the blend mode to multiply, click on the little color swatch and eyedropper the coast color. Opacity all the way up, then click on the contour box (not the arrow on the side—the box itself) and pull the center of the curve downward. Then play with the size and add a little bit of noise. I've got 4% here; a little goes a very long way.
Then I went in with the dodge tool and, with a very large, very soft brush, added a little variation to both the grunge and the clouds layers. There are several tutorials available for making and weathering the parchment. I think RobA has a very nice one for the Gimp that includes putting some water stains on. Water stains work a little differently with a watercolored map, though (examine the stain to the right of the word Boston). To get that saturated look over the water, paint the stains on a new layer with a light-colored brush and set the layer to the saturation blend mode. Then duplicate it and set the new layer to lighten. Then play with the opacities of those two layers until you get something that looks right. Duplicate it again and place the new layer above your land layer, then clip it (hold down alt and click on the line between the two layers—the layer will now only be visible where there are visible pixels in the land layer. Change the blend mode to multiply and again play with the opacity. You could do some more grunging up of the stains, of course, but those blends appear to be making the right changes.
Hope that helps you a bit.
Bryan Ray, visual effects artist
Thanks alot for tutorial and thanks for your time. Sure it helps me.