(It is assumed that treasure hunts won't be overt about the region, but there's no rule against this.)

I would find it cute to have a treasure hunt explicitly for city x, with a lesser prize such as a little gold coin. "Maybe don't book a flight on Air Canada to pick this up". Vancouver for example, or a smaller city. This would also work for local sponsorship.
 
 

What do you think of this as a prize? Twenty $50 bills, a $1,500 little gold coin, a $500 Canadian Tire gift card (provided by the company) and a $500 Skip the Dishes gift card. Different experiences. $3,500.

I'm tempted to make a red triangle $500 Canadian Tire gift card as a prize, for a small city.
 
 
 

There is controversy and discussion involving Carnival cruise lines. Don't quote me on the details. The budget cruise has brought in a lower class of people, and had encouraged a party environment. Cruisers made trouble - fighting for example - and did controversial things. It's black people doing this. But it's more complicated than that. One can find black voices complaining about the behaviour. Carnival stopped rap music, or at least is experimenting with doing so, banned non-electric fans (seems to be a dance thing), bluetooth speakers and loud music. They're cracking down on fighting, marijuana, and I think they're doing something with drinking. I don't think they banned twerking, not formally anyway. The geography of activities on the ship is an issue.

Anyway, discuss it in the comments.