Sea distance calculation

[GustavoBenito_Silva]

Hello, i was asked to create a sea distance calculator for my work (epidemiology  departament at National health Ministery in Argentina).
The objective is to calculate distance between ports first and time in days for each distance depending on vessel speed.
I dont need anything greatly detailed (depth of water is not an issue and so ).
I dont really have a clue on how to start. I have ports lat-long, thats all.

[JoshuaDamron]

Howdy,
  The ideal tool for this task would probably be using the Network Analyst tool, it is an Arc extension so depending on the version of ArcGIs you have you may not have access to it.

You can learn mopre about Network Anlayst in the desktop help:
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//004700000001000000.htm

Does this sound like what you are trying to achieve?

[YU-ENYANG]

I had meet the same problem , calculating  distance from sea.

Here is my solution  "Euclidean Distance"

put feature in  and out put will be raster data.

If your input is line ,the result would calculate inside and outside.