Is this the first time the engine has been opened, assuming it was running like that? Looks to be 8-degrees (if I'm counting teeth right) retarded.
Possibilities:
If an aftermarket cam, that's where it degreed in (unlikely).
I have received timing sets that have been mismarked or not marked at all. Maybe the installer degreed the cam and discovered this and compensated without remarking the gears (also unlikely).
I'm betting that it was installed on a Monday morning or Friday afternoon or right before or after lunch or some time when the installer's mind wasn't on doing a good job.
Anyway, I have been curious about playing with cam timing. Retarding cam timing is supposed to favor output at RPM above peak torque, but with a hit to output everywhere else in the RPM range. That seems like it would be a good idea for (racing) a jet boat since it basically operates at one RPM, however I also think that cruise economy would suffer.