CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (116,230)	$ (6,176)	$ (39,111)
Other comprehensive income (loss):
Foreign currency translation adjustment	(52)	(18)	9
Change in fair value of interest rate swaps, net of reclassification adjustment	1,150	(2,066)	0
Income tax benefit associated with other comprehensive income items	342	0	0
Comprehensive loss	(114,790)	(8,260)	(39,102)
Net (income) attributable to non-controlling interests	0	(119)	(3,810)
Net loss attributable to non-controlling interests of One Water Marine Holdings, LLC	1,648	590	4,329
Foreign currency translation adjustment attributable to non-controlling interest of One Water Marine Holdings, LLC	(2)	2	(1)
Change in fair value of interest rate swaps, net of reclassification adjustment attributable to non-controlling interest of One Water Marine Holdings, LLC	(574)	184	0
Income tax expense associated with other comprehensive income items attributable to non-controlling interest of One Water Marine Holdings, LLC	87	0	0
Comprehensive loss attributable to OneWater Marine, Inc.	$ (113,631)	$ (7,603)	$ (38,584)