NASA Ocean Colour Web:

https://oceancolor.gsfc.nasa.gov

ESA Ocean Colour Climate Change Initiative

https://www.oceancolour.org 

Biogeochemical Argo Global Data Assembly Centres: 

http://biogeochemical-argo.org/data-access.php

CLIVAR and Carbon Hydrographic Data Office (CCHDO): 

http://cchdo.ucsd.edu/ 

Global Synthesis of POC Using Satellite Data calibrated with Transmissometer and POC Data from JGOFS/WOCE

http://people.tamu.edu/~wgardner/~pdgroup//TAMU-SMP.html

OceanGliders Global Data Assembly Centres:

FRA: http://www.ifremer.fr/co/ego/ego/v2/

US: https://gliders.ioos.us/erddap/index.html

AUS:http://imos-data.s3-website-ap-southeast-2.amazonaws.com/?prefix=IMOS/ANFOG/# 

OceanSITES Global Data Assembly Centres: 

http://www.oceansites.org/data/index.html