What Does Pounds of Buoyancy Mean?

Home > Life Jackets & Flotation > What Does Pounds of Buoyancy Mean?

What does "Pounds of Buoyancy" Mean?

The U.S. Coast Guard life jacket classifications specify a minimum pounds of buoyancy for all flotation devices. The pounds of buoyancy rating is how much "dead" weight it will hold up on the surface of the water. In other words a Type I life jacket rated for 22 lbs. of buoyancy must be able to keep 22 lbs. of dense material (such as rocks or metal) afloat.

How, you wonder, does 22 lbs. of buoyancy hold up a 200 lb. person? Let's do the math. Approximately 80% of the human body consists of water. Water in the body has no weight when in the water. So that leaves only 20% of a person’s total body weight that needs to be supported. In the example of a 200 lb. person, that would be 40 lbs.

              Example:    200 lbs. x 20% = 40 lbs.

But the life jacket only has a buoyancy rating of 22 lbs. That still isn’t enough to hold up 40 lbs?

Now take into consideration that on average our bodies also are made up of 15% fat -- and fat actually weighs less than water, so will float on its own. So now you can deduct another 15% of a person's total body weight.

              Example:    200 lbs. x 15% = 30 lbs.

                            40 lbs. - 30 lbs. = 10 lbs.

Now you can see that a 200 lb. person only weighs about 10 pounds in the water. The 22 lbs of buoyancy in your life jacket is more than enough to keep a 200 lb. person afloat.

To shop for a life jacket, see the wide selection in our Life Jackets category.

______________________________________________________________________________________________________________________

Disclaimer: Information on this website is provided only as a guideline, and not to be used for any other purpose. While we strive to obtain accurate product information, we cannot guarantee the accuracy, completeness or timeliness of any product information. We recommend that you do not solely rely on the information presented on this website and that you always read labels, warnings, and directions and other information provided with the product before using a product. For additional information about a product, please contact the manufacturer. The buyer is responsible for choice, fit, and use of any life jacket purchased from Savvyboater.com. By purchasing through this site, the buyer acknowledges this fact and accepts the waiver of any liability against Savvyboater.com. Please boat safely and always wear your life jacket.

Additional questions? Talk with one of our representatives via chat, e-mail, or toll free at 866.560.1330. We are always happy to help.