Dear Bernabè,

tou can try with M_map toolbox of MATLAB:

http://www.eos.ubc.ca/~rich/map.html

m_vec can be used to plot the arrows, and m_pcolor to plot the colors (see as example the attached pubblication)

regards

Milena

Article Surface Geostrophic circulation derived from Lagrangian drif...

This is surely somehow possible in R, possibly with the oceanographic package 'oce' and the function plot.cm()  (plot current meter data), though I didn't try it until now.

Best regards

Armin

Thanks Milena & Armin for your feed-back. 

Milena, those graphics on your publication look terrific. Hope I can generate something similar in my study area. 

Armin, I'll also try with R. I didn't know I could get that output with it. Such a poweRful tool !! 

Cheers!