We've just been away on a holiday which involved a few trips on my Dad's rib, so I bought this.... https://www.force4.co.uk/item/Plastimo/Typhoon-100N-Childs-Life-Jacket/8IV My little girl is 4 months, but they're sold by weight, so I guess you could work out which bracket your LO will be in at 6 months, and buy that one? We went into the shop and the staff recommended it/showed us how to fit it, so I knew it was fit properly and would work, rather than just buying a random one online.
@Elle thank you so much for the recommendation and what a cute model!!
I’d just get a life jacket for 6 month old if you feel safer having them in something! We got one for our son when he was that age x