| Document and Entity Information | Mar. 21, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 21, 2022 |
| Entity Registrant Name | OneWater Marine Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39213 |
| Entity Tax Identification Number | 83-4330138 |
| Entity Address, Address Line One | 6275 Lanier Islands Parkway |
| Entity Address, City or Town | Buford |
| Entity Address, State or Province | GA |
| Entity Address, Postal Zip Code | 30518 |
| City Area Code | 678 |
| Local Phone Number | 541-6300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001772921 |
| Title of 12(b) Security | Class A common stock, par value $0.01 per share |
| Trading Symbol | ONEW |
| Security Exchange Name | NASDAQ |
