In 2013, $7.5 billion was invested in offshore. The previous offshore record was set in 2010 when $12.8 billion was invested globally.
The boost to offshore wind helped increase global clean energy investment by 16% to $310 billion - the first rise in investment since 2011.
Figures from Bloomberg New Energy Finance said there were seven billion-dollar offshore projects to reach final investment decisions (FID) in 2014.
These include the $3.8 billion, 600MW Gemini project off the Netherlands and the $2.6 billion, 402MW Dudgeon development in the UK North Sea.
Investment in onshore and offshore wind rose 11% in 2014 to a record $92.4 billion, according to the figures. Wind investment in 2013 totalled $84.4 billion.
Despite the major boost to offshore, most of which is in Europe, total clean energy investment on the continent only rose 1% to $66 billion.
In Australia, investment in clean energy fell 35% to $3.7 billion, the lowest since 2009, as a result of the government's threat to end the Renewable Energy Target scheme.