CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Revenues
Total revenues	$ 329,611	$ 189,963	$ 543,694	$ 343,661
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales	240,825	145,379	402,472	266,888
Selling, general and administrative expenses	48,348	32,383	83,208	60,688
Depreciation and amortization	1,378	791	2,341	1,551
Transaction costs	368	2,925	568	3,362
Loss on contingent consideration	0	0	377	0
Income from operations	38,692	8,485	54,728	11,172
Other expense (income)
Interest expense - floor plan	330	2,525	1,250	5,184
Interest expense - other	1,215	2,457	2,139	4,310
Change in fair value of warrant liability	0	0	0	(771)
Other expense (income), net	5	52	(89)	65
Total other expense, net	1,550	5,034	3,300	8,788
Income before income tax expense	37,142	3,451	51,428	2,384
Income tax expense	6,550	472	9,061	472
Net income	30,592	2,979	42,367	1,912
Less: Net income attributable to non-controlling interests		103		350
Net (loss) income attributable to One Water Marine Holdings, LLC	20,475	1,085	28,263	1,085
New Boat [Member]
Revenues
Total revenues	239,654	132,719	391,482	235,571
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales	187,147	108,254	309,679	194,209
Pre-Owned Boat [Member]
Revenues
Total revenues	56,082	38,186	94,662	71,257
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales	42,548	31,343	73,000	59,209
Finance & Insurance [Member]
Revenues
Total revenues	11,789	8,083	17,752	12,408
Service, Parts & Other [Member]
Revenues
Total revenues	22,086	10,975	39,798	24,425
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales	$ 11,130	$ 5,782	$ 19,793	$ 13,470
Class A Common Stock [Member]
Other expense (income)
Earnings per share, Basic (in dollars per share)	$ 1.88	$ 0.18	$ 2.61	$ 0.18
Earnings per share, Diluted (in dollars per share)	$ 1.83	$ 0.18	$ 2.55	$ 0.18
Basic weighted-average shares outstanding (in shares)	10,901	6,088	10,838	6,088
Diluted weighted-average shares outstanding (in shares)	11,171	6,088	11,083	6,088
OneWater LLC [Member]
Other expense (income)
Less: Net income attributable to non-controlling interests	$ 10,117	$ 1,791	$ 14,104	$ 477