a berth can reffer to two things. Firstly the a berth can be a bed or sleeping place on a vessle, because of the lack of space in most boats there are range of berth types allowing beds to be fitted wherever possible, these include a quarter, berth, pilot and v berths. secondly a berth can mean a specific place in a harbour or port where a vessle may be berthed this is ussually for loading and unloading.

information from: http://en.wikipedia.org/wiki/Berth_%28moorings%29
http://en.wikipedia.org/wiki/Berth_%28sleeping%29
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