v3.25.1
Cover - shares
 6 Months Ended
Mar. 31, 2025
Apr. 22, 2025
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2025  
Document Transition Report false  
Entity File Number 001-39213  
Entity Registrant Name OneWater Marine Inc.  
Entity Incorporation, State or Country Code DE  
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  
Title of 12(b) Security Class A common stock, par value $0.01 per share  
Trading Symbol ONEW  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Central Index Key 0001772921  
Current Fiscal Year End Date --09-30  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Class A Common Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   16,313,115
Class B Common Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   0