Man, I understand your frustration.
Are you working with a dealer? The reason I ask that is that they don't make engines specifically for the boats, your engine is just the 155NA without the electronic throttle body.
For the PWC's, that would be anything below 2010 for a 155 GTX.
This ECU should run your machine but you will need to marry it to your cluster, so you will need either a dealer or Candoo software.
Here is the part number for a 155 NA 2009
420665783