The event was held on board a boat on November 27, on Mahavir Day.
Activists hoisted Eelam flag and paid floral tributes, said the website.
Meanwhile, radiogagana.com reports that Tilleyampalam Sivanesan alias colonel Soosai headed the Sea Tigers formed in the 1980s and had its main camp in Mullaitivu.
Mahavir Day was also marked in northern and eastern Sri Lanka, Britain, India, France, Germany, Switzerland, Norway, US, Canada, Malaysia, Qatar and Indonesia, it says.