Bests & Worsts Reviews from Amazon

It must seem obvious, but it didn't to me, that to make an object float, it needs to be larger than the same object that doesn't float. The PLB-375 basic unit doesn't float, and it's the size of an old cell phone. The PLB-375 ResQLink+ (plus) is the floating model, and it is significantly larger than the basic unit, beyond what is apparent from the photos on Amazon and the company's website, and beyond what is apparent from the published measurements. The non-plus (+) unit is designed for use on land, and has only a wrist lanyard to attach it to your person, if it needs to be attached at all. It is very small and will fit anywhere in your backpack. If you were floating around the ocean in a lifevest however, it would be undesirable because there isn't any good, quick way to deploy it and attach it above water to a lifevest. The wrist lanyard is the only possible attachment point on the unit, and it doesn't readily lend itself to attachment while deployed. If you accidentally dropped it in the water, it would sink. (I have both units in my hands as I write this.) The (+) version floats and comes with a hoop on each end that holds two sided velcro tape, but has no wrist lanyard. The (+) version uses velcro tape that threads through the unit to attach to a lifevest, so the deployed antenna of the beacon remains OUT OF THE WATER while broadcasting. The velcro just loops around the shoulder strap of the vest. The unit's physical size is greater both because of the built-in flotation chamber on the back of the unit (de-emphasized in the photos) and the space occupied by three layers of velcro, not shown in the photos, also on the back. The flotation chamber adds about 3/8" to the thickness of the unit, and the three layers of velcro add another 1/4", so the flotation and attachment together add about 5/8" to the thickness of the (+) unit. I was tempted to keep the non-floating model because of its extremely small size, but ultimately I kept the floating model, not because it floats, but because of the ease of attachment to a lifevest. If you're going to use the beacon in an aquatic environment where you could be handling the unit in ocean swells and choppy waves, the plus (+) version is the only realistic choice, but it will be larger. If you're strictly a landlubber, get the non-plus (+) version. I think the ACR is the best of what is now available in small PLBs, however I think they could have designed a secure belt clip into the floating back (instead of the velcro) as a means of attaching the unit to the person needing rescue on the water.