Please advise where you are boarding the ship - is it Bridgetown?
Barbados (BGI) (Grantley Adams airport) is 13km (8 miles) east of Bridgetown. Shouldn't take long.
If you flight into Grant Manley Airport is around 6.00PM you may find that the traffic in Bridgetown at that time in the evening can be quite heavy. It may take 35-60 minutes to reach the ship.