отправиться в вольное плавание

[Chucha]

Help me to render this phrase in English. The context is : To let something go its own way.

Thanks to all:)

[Little Mo]

go with the flow

[Truth Seeker]

“to go with the flow “= to follow the crowd = “плыть по течению” (I could be wrong, but it is not what the “asker” is inquiring about).

For "To let someBODY go his/her own way" I would suggest "to let somebody chart his own course"
"To let someTHING go its own way" - "to let it take its course", as in
If you fall ill with a cold, sometimes it is healthier to let nature take its course.