The reason the sail looks odd to you is because that is how it appeared when Electric Boat Company first built it. Wartime experience led captains to cut down the fairwaters to reduce their visual and radar signatures. You can build a very early Gato from this kit as it appeared when champagne was smashed across its bow. Modifications started being incorporated at the shipyards for later builds. Not all Gatos can be built from this kit for another reason, the limber hole shape and arrangement varies among the different shipyards. Granted, this kit purports to be specifically 212, the first boat in the Gato class, so no one is really expecting to build another boat from it. Unlike the Revell 1/72 kit that has features from several different boats incorporated into one, making it correct for virtually none of them save the Cobia, even though it has decals for several.