Dear Alexandria,

You'll find plenty of satellite-derived ocean color data on the Web. Here are some pointers to get you started: at NASA

- SeaWiFS: http://oceancolor.gsfc.nasa.gov/SeaWiFS/

- MODIS: http://oceancolor.gsfc.nasa.gov/cms/

and at ESA

- MERIS: https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/envisat/instruments/meris

- Sentinel 3: https://earth.esa.int/web/guest/missions/esa-future-missions/sentinel-3

Sentinel-3 is a brand-new satellite (launched 16 February 2016); the data may not be accessible yet but will be released in due time.

All of these are freely available, and existing global data archives cover more than two decades already.Good luck. Michel.

Dear Alexandria,

The first data acquired by Sentinel-3 of ESA are available now. You can find them at : https://scihub.copernicus.eu/dhus/

For Sentinel-3 User's Guide: https://sentinel.esa.int/web/sentinel/user-guides/sentinel-3-olci

Proccessing sofftware : https://sentinel.esa.int/web/sentinel/toolboxes/sentinel-3

& for researchers that work with this type of data: http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-3/Estonia_s_first_contract_with_ESA_focuses_on_ocean_health

I recommended Ms. Anu Reinart and her research's group: http://www.to.ee/eng/news/eFJlMjU1NzZz/ready_to_use_copernicus_sentinel_3_data

Best regards, Luz

Depending on what types of ocean data you are looking for from NASA you can try the ocean color site indicated above or the one at the Physical Oceanography Distributed Active Archive Center (PO.DAAC) - http://podaac.jpl.nasa.gov/. (In general you can start from https://earthdata.nasa.gov to get at NASA's Earth science data held at any of the 12 discipline-oriented DAACs, two of which are the Ocean Biology DAAC - OB.DAAC indicated above vy Michel M. Verstraete and PO.DAAC, which I have pointed to here).

Thank you, Mr. Verstraete, Ms. Saavedra and Mr. Ramapriyan for all of your helpful answers. 

Don't forget the Landsat missions.