Group sizes are about 20.
20 groups in a day.
=£1000 a day
Say actors get paid £9ph. Probably 8 actors a day for Dungeons working 7 hours a day, £504 a day.
Plus ride staff to operate the boat ride (they won't be actors, just ride staff in a character), engineers/technicians getting the ride ready, plus the actual running of the attraction probably adds another £100-150 in simple terms.
So yeah, it'd make a couple of hundred quid if it ran at full capacity.