Your jib is forgeted, and there's no mainsail. From a sailor's point of view this sure ain't seaworthy.
The jib (the front triangle everyone's talking about) should be hung on a line between the top of the foremast and the bowsprit. What you've got right now looks more like a forestaysail, which is hung between the bow and the first or second yard on the foremast. On a big ship like this (I assume a clipper ship or frigate is the look you're going for) there's usually a forestaysail and one or two jibs to catch the wind a bit better.
The mainsail is a big, roughly triangular sail that's on a boom and raised from the back of the mainsail; it actually provides most of the power for the boat if the big square sails are struck. It tends to steer the boat toward the wind, counteracting the jibs which steer the boat away from the wind and ensuring balance (by playing the two sets of sails off each other, a lot of boats can be steered without even using the rudder.) It's pretty hard to operate a boat without a mainsail, unless you're just coming into port.
That said, it's a very good build.
