The berth allocation problem is to allocate berths (i.e., sections of the quayside) to ships arriving in a container port in order to minimize the sum of their waiting and cargo handling times. In the static case, ships are assumed to arrive before the berths become available; in the dynamic case they can arrive before or after. We discuss recent models for both problems, correct one formulation, and provide a compact reformulation for the dynamic case. The computational results for problems that are moderate in size but realistic, with up to 10 berths and 50 ships, using both formulations and CPLEX, are reported.