When open water is available and the set is located a few meters above the water level, the most economic setup is to deploy a number of non-collapsible suction lines to the water and prime the main pump with a vacuum priming system.
We select pumps on an excellent NPSH so these systems operate well up to 5 or 6 meters above the water level.
Our vacuum priming system is fully automatic, it warns the operator in case of air leaks and primes the pump in a couple of minutes.
An example of this open water solution can be found here.