A broader application of biocomposites still faces many challenges regarding structural integrity, environmental resistance, and biodegradability. These issues are particularly important when their marine applications are considered. Therefore, this paper seeks to address the hygroscopicity, mechanical properties, and biofouling resistance of biocomposites made of epoxy resin with 28 m% bio-based carbon content reinforced with flax and hemp fibers. A series of experiments are performed to acquire water absorption rates, saturation limits, mass increase, tensile and flexural properties, interlaminar shear strength, impact resistance, and mass gain due to biofouling. All tests of mechanical properties are conducted before and after immersion in seawater. The acquired saturation limits of flax/epoxy and hemp/epoxy biocomposites amount to 7.5% and 9.8%, respectively. The water uptake causes the tensile and flexural properties to decrease by 26–74%, while interlaminar and impact strength increase for flax/epoxy and decrease for hemp/epoxy biocomposites. In addition, it is observed that in almost all cases, flax/epoxy has superior properties compared with hemp/epoxy biocomposites. It is expected that this research will motivate naval architects and classification societies to consider biocomposites as prospective hull materials that provide both structural integrity and environmental sustainability.

Three-dimensional modelling software tools enable the creation of a digital replica of the product—“Digital Twin”—a representative of “Virtual Reality” as one of the prominent trends of Industry 4.0. The development of the Digital Twin can start simultaneously with the development of the product, primarily for the purpose of selecting optimal technical and technological solutions prior to and during physical construction, and, ultimately, with the intention of managing the entire product life cycle. The Digital Twin, as one of the key technological achievements in the implementation of the business system transformation from traditional to smart, should also be recognized as the cornerstone of the “Shipyard 4.0” model, i.e., its “Cyber-Physical Space.” This paper is based on statistical and empirical data of the observed shipyard with the aim to represent the significance of the Digital Twin ship in preserving and improving the competitiveness of the shipbuilding industry. Namely, with the emphasis this article places on the contribution of “advanced outfitting” in achieving savings in the shipbuilding process as well as its role in attaining high standards of environmental protection and workplace safety, the importance of its further improvement is an obvious conclusion—with Digital Twin being one of the recognized tools for this purpose.