After resting they decided to go for a swim. The depth of the water is 15 times Dean's height. Dean is 4 feet taller than Ron. If Ron stands at 13 feet how deep was the water?
First, we need to find out how tall Dean is. We know that Dean is 4 feet taller than Ron, so we can add 4 feet to Ron's height to find out Dean's height. 

Ron is 13 feet tall, so Dean is 13 + 4 = 17 feet tall. 

Now we know that the depth of the water is 15 times Dean's height. So we can multiply 15 by 17 to find out how deep the water is. 

15 times 17 is equal to 15 x 17 = 255. 

So the depth of the water is 255 feet.