As if owners didn't have enough headaches just now, Grenada has chipped in with a warning for vessels to steer clear of an underwater volcano showing signs of increased seismic activity.

The Caribbean island has imposed a 5km exclusion zone around the wonderfully named Kick 'em Jenny, 8km from shore.

The alert for the volcano was raised to the appropriate lava-coloured orange, meaning an eruption could take place within 24 hours, the BBC reported.