I persoanlly would not go very far offshore without a bomb-proof roll or wet exit and re-entry skills. Imagine re-entry in 6 to 8 foot seas. If caught in big water, the offshore PFD is good to have but the trade off is that they are so bulky as to effect paddling in control so pick your poison. Here’s some info from the USCG:
PFDs work on the principle of buoyancy, and help keep a wearer’s head above water in case he/she physically cannot. There are different ratings for different types of PFDs. This rating depends on the buoyancy needed and the application of the device. The devices are rated as Type I, II, III, IV and V. These PFDs are required and/or recommended by the USCG and state law enforcement agencies for different applications. The minimum amount of buoyancy for each device type is listed below:
Type I = 22 lbs.
Type II (Near Shore Buoyant Vest) = 15.5 lbs.
Type III (Flotation Aid) = 15.5 lbs.
Type IV = 16.5 lbs.
Type V = 15.5 – 22 lbs.
According to the Personal Flotation Device Manufacturer’s Association (PFDMA) most adults need an extra 22 lbs. of buoyancy in comparison to their body weight to keep their heads above water.
The following list explains the types of PFD’s and what they are recommended by the USCG to be used for and when they are required.
[Type I PFD’s]These are the best devices for all waters, open ocean, rough seas or remote water where rescue may be slow in coming. This type of device is also used as abandon-ship life jackets for commercial vessels and all vessels carrying passengers for hire.
Type II PFD’s – [Near-shore buoyant vests]For general boating activities, calm inland waters or where there is a good chance for fast rescue.
[Type III PFD’s ] Flotation aids: For general boating or specialized activity that is marked on the device (such as water skiing, canoeing, kayaking, hunting etc.). These devices are best for calm inland waters or where there is a good chance for fast rescue.
Type IV PFD’s – [Throwable devices:]these devices are designed to be thrown to persons in distress. Often this type of device includes boat seat cushions, ring buoys and horseshoe buoys. These are not designed to be worn and should be supplemented by a wearable PFD. Both the throwable and wearable devices should be readily available for emergency situations.
[Type V PFD’s]Special use devices: Used only for special uses and conditions. Typically these are labeled with their limits of use. Commonly these flotation devices are used for canoeing/kayaking, boardsailing, deck suits, [work vests] for commercial vessels and man over-board situations and law enforcement. Also included in this classification are [hybrid inflatables.]Hybrid inflatables are deflated devices and can be inflated on demand. These devices can have a buoyancy of between 22 and 34 lbs.
An important part of having and using a PFD is the fit. PFDs should fit comfortably and snug. It is important to try the PFD on before use. It should not ride up your body. To test whether the PFD has the correct buoyancy for your weight, when lying on your back in water and relaxing, the PFD should keep your chin well above water. If it does not, a device with higher buoyancy is needed.
United States Coast Guard