Note 5 - Stockholders' Equity and Dilutive Equity Instruments - Dilutive Equity Instruments (Details) - shares	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Common stock, shares outstanding (in shares)	52,487,862	52,259,303	50,895,235
Total (in shares)	53,335,022		52,596,884
Restricted Stock Units and Stock Options [Member]
Common stock shares reserved (in shares)	689,806		1,520,226
New Creditor Warrants [Member]
Common stock shares reserved (in shares)	76,175		81,244
GulfMark Creditor Warrants [Member]
Common stock shares reserved (in shares)	81,179		100,179