A bigger than expected dividend announced by Okeanis Eco Tankers (OET) on Friday could be the last for some time as tanker markets head south.

This is according to Norwegian investment bank Cleaves Securities, whose head of research Joakim Hannisdahl called the dividend "very handsome" at $0.75 for the second quarter.

"We had expected the company to be conservative and pay out only 50% due to current market conditions.