We did the river float on our Yorktown Clipper cruise. We'd docked in Haines and rode the "school bus" to where the rafts were. The weather was perfect (late August), and it was a calm float through beautiful scenery. Lots of eagles!
Where we waited on the riverbank to board the boats, the mosquitos were numerous and aggressive. My wife had used Avon Skin So Soft, and was not bothered. I had no protection, and got six or eight bites, which developed into huge welts that lasted for weeks! This was the only place we encountered mosquitos, and I'll take repellant when we go back...
Take Care, Bob