We went on a trip on the Desert Belle and thoroughly enjoyed it! The ambient temperature was 105+, but on the trip it was very pleasant. The lake is a busy place with boaters, kayakers, etc., but the boat trip is pleasant.
The tour is on Saguaro Lake in Mesa (in Tonto National Forest). The trip is 1 1/2 hours on the boat and takes you on a 10 mile narrated trip (out and back) on the lake and through the canyons of the area. The boat is comfortable the staff is great and knowledgeable.
On the trip we spotted a bald eagle. (The captain told us that they had seen the nesting pair the night before as well as a pronghorn sheep on the steep canyons side). The trip is very enjoyable.
We opted for the "preferred" ticket ($25) over the regular ticket ($20)... It allows you early boarding (for seat selection) and gets you a beverage (alcoholic or non) or a snack (popcorn or other) and was well worth it.
The captain provided a commentary about the area and the wildlife that was very informative and entertaining.