Translation guide
A flotation device worn to keep a person afloat in water, commonly used on boats or during water activities.
life vest
General term; also ライフジャケット in casual contexts.
A wearable flotation device for safety on boats or near water.
The most common and general term for a life vest, used in official and everyday contexts.
Please put on a life vest before boarding the boat.
A common loanword from English, widely understood and used in casual and recreational settings.
I wear a life jacket when I go canoeing.
Literally 'float ring', this refers to a ring-shaped flotation device, often used by children or for play, not a standard safety vest.
Not a substitute for a proper life vest in safety situations; it's a toy or leisure item.
The child is using a float ring in the pool.
A life vest that inflates, often used for water sports or aviation.
Specifically an inflatable life vest, used in technical or official contexts.
This inflatable life vest inflates automatically.
The loanword version for inflatable life jacket, common in recreational boating and fishing.
救命胴衣 is the formal, standard term used in safety regulations and official documents. ライフジャケット is a loanword that is very common in everyday speech, especially in recreational settings. Both refer to the same item, but 救命胴衣 is preferred in written instructions or formal announcements.
浮き輪 (float ring) is a toy or leisure item and should not be used as a safety device. Do not use it to translate 'life vest' in safety contexts.
Make sure your life vest is properly fastened.
Children must wear life vests at all times on the boat.
I wear an inflatable life jacket when fishing.