Planking of this ship was not of a clinker-built type as a tile of a house roof and as they did it earlier but it was a carvel-built planking: one board closely coincided with the other. Though this type of planking was known before, invention of such a method of planking belonged to a shipmaster from Brittany Julian who called this method a 'carvel' or 'carveel'. Later on the name of such a planking passed into the name of a vessel/s type - carvel. Carvels were finer than koggs and had a better sail rigging and that was why medieval discovers chose those solid, fast and capacious ships. Carvels had the following characteristic features - high boards, deep flexure of the deck in amidships and a mixed sail rigging. Only the fore mast carried a square sail. Lateen sails on the fore-and-aft yards of the main and the mizzen masts allowed vessels to go close to the wind.