The dog that would most often be aboard has a collapsed trachea, both cervical and intrathoracic, so cannot wear a collar or any "vest" that rises above the sternum. It took months to find a suitable everyday harness.
A thorough search of PFDs shows they all have some kind of front enclosure or wraparound. Obviously that is ideal to eliminate the chance of him swimming out of it.
I fear just floating in one of these would put unwanted pressure on the neck and throat.
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Has anyone come across this rare predicament or is using a brand that fits low in front?