All mobile phone GPS applications show you a solid blue screen when you're at sea. Since there's no nautical map app available for Thailand, I decided to have a go at creating my own phone app.

Basic idea: have the app function the same way as google maps, but offline (mobile data connections are pretty useless at sea) and showing the depths and nearby dive locations.

Sofar so good. Now it comes down to getting the actual nautical charts. I managed to get my hands on a few Thai nautical charts, like this one from the similans, chart T307b:

Does anyone know where I can get these maps? Preferably digital....

Garmin Blue Charts. They have absolute everything.

As I don't want troubles with the mods, I can only tell "Google is your friend"

Everything can be found on the shady places on the internet....

Hi Prasert,

I think you are looking for seafloor depth information. Such information referred to as bathymetry is available from Gebco. The data is derived from satellite scan and are in .nc format and unless you are familiar with using GIS software, you will not be able to read/view it.

I can generate these bathymetry nautical charts for you for the whole of the Gulf of Thailand if you wish or some island which you want.

I normally load this in my Garmin gps as a Kmz file (Google Earth format) which can also be viewed on Google Earth in your laptop.

You may also wish to check out 'OpenCPN', a pc based free chartplotter which you can connect to your gps and navigate with this

nautical chart.

Contact me with more detail of what you need.