## 1 Introduction  
In recent years, there has been a growing interest in the development of marine infrastructures and technologies to harness maritime resources [1, 2, 3, 4, 5, 6]. These efforts aim at supporting the expanding global population and promoting the sustainability of human activities [7, 8, 9]. Significant strides have been made, ranging from the creation of modular floating structures for energy generation and artificial energy islands, to the development of modular artificial reef structures dedicated to the protection and restoration of marine ecosystems [10, 11, 12, 13, 14]. In fact, artificial reefs (ARs) might contribute to multiple other purposes such as increasing fisheries yield [15], recreational dive tourism [16], improving surf conditions [17], coastal protection [2, 18, 19], and preventing bottom trawling [20]. Some authors have highlighted the importance of designing ARs specifically for the ecosystems projected to be enhanced [8, 12]. However, according to the literature, the purpose for which artificial reefs have been created is seldom revealed [6]. Despite all the advantages, these innovative structures face numerous challenges characteristic of a new era of coastal and maritime engineering [21; 22; 23]. These challenges include structural complexity and durability requirements, complex hydrodynamic interactions with ocean currents, and suitability for sea operations. There is an urgent need for new approaches that not only address these problems effectively but also prioritize ecologically friendly solutions, bio-receptiveness, efficiency, and resilience. This is essential for fostering a sustainable and balanced relationship between human activities and the environment [4; 21; 24; 25; 26; 27; 28]. Over time, the design of ARs has predominantly relied on empirical methods, guided by subjective judgments and assessments. In some cases, this approach was limited to sinking structures without the adoption of a clear design process. However, growing interest in artificial reef technology led to the development of several guidelines and recommendations [29; 30; 31; 32], as well as frameworks for the development of purpose-oriented ARs. In general, these frameworks address functional aspects and provide a global view of the entire process and, to some extent, also address the structural design, albeit superficially. Recently, [PERSON] proposed a conceptual framework to design artificial reefs, which includes a design component that focuses mainly on geometric design, materials, and manufacturing [33; 34]. [PERSON] et al. (2022) proposed a new general and integrated conceptual framework to guide the design of AR units by adopting an ecosystem ecology perspective [35]. The flowchart is composed of three main parts: (i) marine ecosystem ecology model, (ii) AR-ecosystem index transformation, and (iii) the stability analysis. Although there is no detailed framework for the structural design, the general methodology highlights this aspect. The authors presented also a methodology based on geographic information systems (GISs) to determine the best area for installing ARs in a specific estuary considering the geomorphological, hydrodynamic, and bathymetric characteristics of the area, as well as the distance to the harbour and economic factors [36]. ARs designed for surfing show a robust and heavy morphology, similar to breakwaters, following similar design principles [17]. A preliminary design achieved step by step, making use of the theory and state of the art of multifunctional artificial reefs for surfing, was proposed by [PERSON] [17; 26; 37; 38]. On the other hand, the geometry complexity of ARs is also an important aspect in other cases, and some works have found that increasing reef complexity has a significant and positive impact on fish species flourishing, density, and increased biomass [39; 40]. Therefore, in recent years there has been a demand for modular, slender, and complex geometries for ARs.