The cog was discovered in 2011, during preparations for deepening the fairway in the mouth of the IJssel.
Rijkswaterstaat said at the time that the cog was in exceptionally good condition. Most of the wreckage previously found have been wholly or partly dismembered and are not complete. The IJsselkogge is one of only three cogs that have been preserved. Others were found in Bremen and Doel (Belgium).
The cog was developed in the thirteenth century as a successor to the flat-bottomed boats that were common until then. The ship was much more seaworthy and could carry much more cargo. This type of ship was used for trade with cities on the Baltic Sea.
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