A 30m long workboat has three waterlines at 1m intervals measured from the keel and is running in sea water. The widths of the waterplane at DWL (commencing from the bow) are 0m, 3.6m, 5.6m, 6.0m, 6.0m, 5.6m and 4.8m respectively. The waterplane areas at other two waterlines are 104 m2 and 57 m2 respectively.