In an Internet-dominated era, there is a plethora of online, free, resources that will help any marine researcher to easily achieve any goal. Here I suggest those I particularly find useful and use in my day- to-day research.
Statistical analysis package, including a wide number of plugins that will allow you to perform whatever test you may be interested. One of my favorites is: RcmdrPlugin.EZR. RCommander operates under R, but providing a user-friendly enviroment. Just discover new plugins.
Amazing tool to visualize and acquire data for a range of oceanographic data derive from satellite. Just clicking, a surplus of data will pop-up.
Great tool to calculate secondary productivity from population size-structure data using literature algorithms.
EstimateS is an easy package to compute species richness and species density through rarefraction. Particularly useful for those doing anything with biodiversity studies and avoid confusion between species density and species richness.
Tool (restricted to the Iberian Peninsula) to derive wave energy data as rasters for any location across Spain and Portugal.
Data series for a range of buoys across Spain that supply info on different attributes of waves.
Layers containing bathymetric and cartography for different areas of the Canary Islands. Just download the layers and open them up in Google Earth.