The answer is it depends on the bowling ball.
This is the same reason boats can float even though they weight thousands and thousands of pounds. They take up less mass then the volume of water they are displacing.
When the ball is submerged in the water, it displaces its volume in water. According to Archimedes’ principle, the water can “push back” with a force (buoyancy) equal to the weight of the water that has been displaced.
The magic number for a bowling ball to float is 12lbs, when the ball is 12.5lbs then it will sink.
So to be able to make a bowling ball float it has to be below 12 lbs or less like I had with the 8lb ball and you saw 12.5lbs and 14 lb ball sank.