What are the advantages of jets?

Looking for deals in the 25hp range. What are the disadvantages? They don't do slow speed well, correct?

Much more thirsty in fuel and/oil and less efficient that a prop for same HP rating. But if you are in rocky areas or the shallows all the time OR ... worse, don't know the waters ahead of you (look up all the awesome Alaskan rivers jet boat videos) ... then they most certainly have their place!

I've read that reverse is lacking with them. They do have their place in skinny water though.

Jets are less efficient so you'll need roughly 50% more horsepower. If you need a 25hp outboard, get a 40hp jet.

Jets let you run in only inches of water without having to worry about damaging your prop. There are lots of times when I wish I had one.

I have one, and I wouldn't want one except to run a rock strewn shallow river that I fish.

Almost none in the 25 HP range unless you have a canoe.

they don't turn well, they don't reverse well, they use a lot of fuel, they are noisier than a prop drive, they require a little more maintenance on the foot, slow speed maneuvering is mostly useless, can't turn without using the throttle (or can't turn very well), slower top speed, yes if you need a 25hp you have to get a 40hp motor and adapt a jet to it, which reduces the overall power to somewhere around 30hp. I don't know how other motor builders are but if you order a yamaha jet-specific motor, it is rated for the actual jet foot power (a 40hp powerhead will have a 30hp cowling but the powerhead makes around 40hp). The ECU for a jet is different than for a prop. Idle fueling and air and spark is different, among other things.

I have seen maybe 4 actual 25hp jets. A 25hp powerhead with a jet foot is about 18hp. One of those was a yamaha 25 twin cyl/twin carb 2 stroke. Talk about noisy. It went by me on the river and I thought man is that guy ever gonna let off the throttle? Well...I think about 25 minutes later he finally got so far away that it was inaudible. He was going maybe 10 mph upriver in a 2.5mph current, full throttle the entire time. Another one I remember was a mercury 25 with a jet foot. Still really noisy. The 4 stroke stuff is much quieter but still a lot louder than a propeller driven outboard.

but if you're running a shallow gravel stream/lake/river, with the right hull they are awesome

Everything else, a propeller is usually a better setup.

Everyone I know who has one loves it about 20% of the time. 80% of the time they hate it. Most of them are professional guides and they're mostly required to get their clients where the fish are at

there's been about 10 times in 10 years I wish I had one. Of those maybe 10 times, about 8 were to get over really shallow areas (less than a foot deep). The other two times? Other boaters who tend to fish too closely....with a jet, tilt it up a little, hammer down. Oops, sorry did you get a little wet? Power tilt is best for that....

Todd summed it up excellent. I ALMOST went with a jet on my last boat. I rigged up a prop guard up on my motor that works for my application that gets me by just fine for all the reasons he outlined.

I hunt and fish in trash strewn water many times at night. Some times in shallow water, but for the most part I don't have to have a jet. So I don't use one for the reasons he outlined. Many times I need to maneuver fast and close and a jet is terrible about that.

rented one on the white river yesterday (20' supreme with 40/30 mercury jet)

Loved it the 2 times I was running a shoal in 5 or 6" of water. Rest of the time it was just noisy and fuel thirsty. top speed upriver was 16 mph, down about 19. But the boat is on plane at like 5mph. Just the way the hull is shaped makes it plane very quickly.

I run the same stretch of river with my war eagle, although I generally don't go across the shoal with it. I have but the water was a little deeper, maybe a foot. Shallow yesterday, plus I didn't feel like dragging my boat 100 miles; just as easy to rent one of theirs

the water is misleading. Few times I've taken my boat, water appears to be less than a foot deep, then you stick the tip of a fishing rod down to the bottom to find that your 7'6" rod won't touch the gravel bottom. But yesterday I stuck the tip of my 7'6" rod out on the shoal and two of the line guides went under and the tip finally touched the gravel. Roughly 6 inches. With a 4.3mph current, you look down and watch the gravel bottom fly past, ya think you're really moving but you're really not going that fast.