"Back to the Future - the culture, history and traditions of the sea" runs from tomorrow to March 6.
The week provided special opportunities to experience the beauty and mysteries of, and learn more about, the marine environment, national Seaweek co-ordinator Mels Marton said.
"Back to the Future encourages exploration of our connections with the sea and links them to future directions," Ms Marton said.
In Otago, the week will begin with a field trip to Victory Beach tomorrow, and an Ocean Open Day complete with the revealing of Autahi the leopard seal at Otago Museum on Sunday.
The fifth annual coastal clean-up will be held on March 6, giving people the opportunity to clean up the region's beaches.
Co-ordinator Liz Sherwood said the Department of Conservation and Dunedin City Council urged people to take part and collect inorganic rubbish from beaches.
"Rubbish on our shores and in the ocean is hazardous to us and to wildlife."
Other events in Dunedin include talks about Otago's hectors dolphins, and viewings of the film Water Whisperers Tangaroa at Oamaru (February 28) and Balclutha (March 2).
Dunedin City Council is urging children to enter a poster competition describing what Dunedin's dune vegetation used to look like, as part of Seaweek.
