We recently took my 87 year old agile father in law out on our lagoon for 2 weeks.

He even did the walk at the baths to devils Bay and back. He made us nervous.

As others said, getting in an out of the dinghy is a little more challenging depending on the individuals mobility.

I once met a 94 year old getting into a dinghy at Cooper. She had a couple middle age grandsons helping her.

Maybe you can show them a you tube video that includes boarding the boat from the dinghy.

Plan on very sheltered anchorages.

When you do go somewhere like leverick, rent a car so they can go to the baths and Savanah Bay.

Ultimately give them the choice.