Expert System - Sailing Ships by McGoo Software

Based on the responses you have made:

The vessel is probably a Brigantine

Conclusion Notes:

This ship has just 2 masts with square sails present only on the first mast.

Expert System Rule:

IF the number of masts on the vessel is 2 only
AND there are square sails on first mast only
THEN the vessel is probably a Brigantine.

Calculated Certainty Factor: 0.65 = probably