Police sources say a suspicious small boat was seen leaving the scene of the fire. The Gros Islet Police Station received the report at around 5 a.m.
The boats are owned by Earl Lionel of Edgewater, Gros Islet.
One of the boats, a 42-foot yacht valued at about $180,000 US, was totally destroyed. A much smaller boat, which was anchored close to the larger boat, caught fire and sustained extensive damages.