Loans Payable - Note 7 - Monaco 2018 - Additional Information (Detail) - Note 7 - Monaco 2018 [Member] - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Debt Instrument [Line Items]
Loan amount borrowed			$ 1,000,000
Interest rate, stated percentage	10.00%
Agreement description	During the period ended March 31, 2018, Monaco advanced us $1.0 million that was applied to a loan agreement that was executed on April 20, 2018. Monaco also agreed to treat $99,366 of back rent owed by us to Monaco as part of this loan resulting in an aggregate principal amount of $1,099,366 at December 31, 2019 and 2018. The indebtedness bears interest at 10.0% percent per year. All principal and any unpaid interest is to be payable on the first anniversary of this agreement, April 20, 2019. This debt is secured by cash proceeds, if any, from our future shipwreck projects we have contracted with Magellan. As additional consideration, their share purchase option expiration date, as discussed in Note 1 – Monaco 2014 and Note 2 – Monaco 2016 above, has been extended from 30 days to seven months after the note becomes paid in full. For the twelve months ended December 31, 2019 and 2018, accrued interest in the amount of $123,466 and $79,539, respectively, was recorded.
Back rent considered as part of loan			$ 99,366,000,000
Aggregate amount issuable	$ 1,099,367	$ 1,099,367
Accrued interest	$ 123,466	$ 79,539