Paddling a Kayak is very good exercise and lots of fun too.
In just an hour of paddling a Kayak you could burn off 102 calories for every hour of kayaking so the longer and further you paddle your kayak the more calories you can and will burn off and you'll have fun in the process of losing weight when kayaking.
If you do extreme kayaking and do an even better workout then you could burn off as much as 400 to 450 calories in an hour of extreme kayaking.
If you're new to kayaking then you should start out with regular kayaking until you get more experienced and then step up to the more advanced kayaking and when you do you'll see a good significant amount of weight loss.
I love to go kayaking and I've lost quite a bit of weight when doing so and it helps to keep my weight off as well and I have lots of fun going kayaking and seeing the sights.