Cover - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 28, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Entity File Number	0-30351
Entity Registrant Name	DEEP DOWN, INC.
Entity Central Index Key	0001110607
Entity Tax Identification Number	75-2263732
Entity Incorporation, State or Country Code	NV
Entity Address, Address Line One	18511 Beaumont Highway
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77049
City Area Code	(281)
Local Phone Number	517-5000
Title of 12(g) Security	Common Stock, $0.001 par value
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 8,672,205
Entity Common Stock, Shares Outstanding		12,035,261
Auditor Name	Moss Adams, LLP
Auditor Location	Houston, Texas
Auditor Firm ID	659