Boat hulls built of Fiber Reinforced Plastic (FRP) undergo greater resistance to bending stresses has required the use of sandwich constructions to give high strength to weight ratio, with carbon fiber skins and honeycomb or foam cores. ‘High tech’ boats such as Americas Cup racing yachts for Oracle BMW , large super yachts as ‘Mirabella V’ and fast patrol/rescue craft such RNLI Lifeboats, now utilize this construction throughout.

Forming a structure from many different materials in the form of a composite increases the chance that a weakness is built into the final product. By the nature of their construction marine composites require 100% inspection. Statistical sampling on a grid principle has historically given results for residual life on homogeneous metal plates on marine vessels, however, composites by there nature are inhomogeneous. The risk of missing a disbond or debonded areas is not acceptable The problems therefore facing NDE inspections are that large areas require to be 100% inspected in a relatively short time frame, with a high degree of sensitivity.

Shearography testing of a marine vessel hull

Laser Shearography offers the advantage to inspect these advanced composites. This NDE technology is able to detect weaknesses in the composite caused by disbonds and un-bonds or by inferior adhesive bonds. The same parameters are then used to validate repairs. Rapid yet sensitive inspections at over 5 to 10 sq meters per hour, with overlapping scans giving over 100% coverage, are not uncommon.

Laser Technology Inc. provides this boat inspection services to detect any hull damage and its surrounding area. LTI will supply a Complete LTI-5200 Laser Shearography system, including camera, laser and vacuum head, with vacuum system and interconnecting cabling. LTI will mark all areas that are found to have defect indications and save all data to be supplied in a formal report. The inspection time is dependent on the overall size of the boat. Typically most boat hulls and surrounding areas can be inspected well within with in a week’s time.

For more information or to schedule a boat inspection please contact Christa Ditlow at Phone: 610-631-5043 x10 or email: