When will underwater hull inspections be performed by laser scanners?
Large ships are inspected and cleaned every 4-5 years and painted every 8-10 years, in order to improve vessel performance and to demonstrate owners’ commitment to safeguarding the structural integrity of the ship.[1, 2, 3] Inspections, cleaning, and painting, are performed by trained specialists, and dry dock inspections are estimated to cost shipowners US$279mn globally/year. Servicing of ship hulls is costly, imprecise, time-consuming, of limited accuracy, and subject to the cumulative fatigue of workers.[3, 5, 6]
Yearly damage to assets from marine corrosion is between US$50-80 bn. In 2017, 40% of marine casualties are the result of structural failures from corrosive deterioration and is the single largest factor leading to such failures.[8, 1]
Laser scanning is an emerging technology that can provide 3-D scans at high resolution. Compared to manual inspection, this method may increase the accuracy and reliability of the detection and measurement of corrosion. However, the challenge of applying 3-D laser technology underwater, and the constraints of working in confined spaces, have so far hindered their implementation.
 Ortiz, F., Pastor, J. a., Alvarez, B., Iborra, A., Ortega, N.,Rodriguez, D. and Conesa, C., 2007. Robots for hull ship cleaning. In: IEEE International Symposium on Industrial Electronics,pp. 2077–2082.
http://docs.trb.org/prp/14-4429.pdf (Own estimate using some estimates from the paper. With an estimated inspection cost of 3,500 to 15,000 USD per ship for annual inspection; the average inspection cost is 9,250 USD. With three different types of inspections, we calculated the cost of drydock inspection as 3,083.3 USD. Finally, to calculated the potential market size by multiplying this number by the total number of large ships in the ocean [90,715 in 2017; see  for an updated number] The number above is a rough estimate, which can be biased so it should not be used for further research and authors of this survey should not be held accountable or responsible for any decisions taking its background in the estimate.)
 Biskup, K., Arias, P., Lorenzo, H. and Armesto, J., 2007. Application of terrestrial laser scanning for shipbuilding. In: IAPRSWorkshop on Laser Scanning, pp. 56–61.
 Navarro, P., Iborra, A., Fern ́andez, C., S ́anchez, P. and Suard ̈ıaz,J., 2010. A sensor system for the detection of hull surface defects.Sensors pp. 7067–7081