Croaker
Landlubber
I spotted the line in Shipsinit.c that allows you to use custom sails. Soleyru and the ghost ship are pretty much the only ones that use them. I made a slightly darker silk with a skull emboss for my custom SeaWolf.

Add the bolded line anywhere in your Shipinit.c text and place the attached texture in \RESOURCE\Textures\Ships
Id love to find where actual emblems are added because I see ships in the game using them, but until then, textured sails arent bad.

Add the bolded line anywhere in your Shipinit.c text and place the attached texture in \RESOURCE\Textures\Ships
refShip.SailorCrew = 500;
refShip.SpeedRate = 20.0;
refShip.TurnRate = 45.0;
refShip.Price = 70500;
refShip.HP = 10000;
refShip.SP = 100;
refship.EmblemedSails.normalTex = "ships\parus_pirate.tga";
//refShip.AbordageLocation = "Boarding Deck_02";
refship.CabinType = "Cabin_Medium"; // boal 28.03.05
refship.Type.Merchant = false;
refship.Type.War = true;
refShip.fWindAgainstSpeed = 2.0;
refShip.sea_enchantment = 1.8;
refShip.lowpolycrew = 12;
refShip.buildtime = 60
Id love to find where actual emblems are added because I see ships in the game using them, but until then, textured sails arent bad.