Search Results (186)

More than 2000 State and merchant vessels lie on the seabed of maritime Southeast Asia, the material legacy of the Second World War. This article asks whether such wrecks can serve to form habits of cooperation, and what might be gained by doing so. Drawing on the concept of heritage diplomacy and focusing on seven Allied wrecks lost in the waters of Indonesia, Malaysia and Timor-Leste, it identifies three dimensions through which sunken military heritage can foster cooperation: affect, the capacity of wrecks to mobilize public and political attention; necessity, the environmental and ethical pressures that compel engagement; and function, the mechanisms that convert engagement into sustained cooperation. It finds that cooperation is most durably realized below the level of the state, that affect and necessity rarely produce cooperation unless relational infrastructure is already in place, and that these relationships generate commemoration far more readily than they do custodianship. Heritage is present in the region’s security architecture, but is rarely used deliberately. The article concludes by arguing that sunken warships are an under-utilized, low-threshold instrument of diplomacy in the contested space of maritime Southeast Asia. Full article

Illegal industrial-scale salvage of World War II shipwrecks across the Asia–Pacific has escalated over the past decade, resulting in the destruction of historically significant naval vessels, war graves, and maritime heritage sites. Once protected by remoteness, depth, or sovereign immunity, wrecks such as HMS Prince of Wales, HMS Repulse, HNLMS De Ruyter, HNLMS Java, HMAS Perth (I), and USS Houston have been systematically stripped or entirely removed. Salvors now employ industrial equipment to extract large quantities of steel, copper, and other valuable materials, typically operating without permits or in poorly monitored waters. These activities erase archaeological context, disturb human remains, and create significant environmental harm, including fuel-oil releases, sediment resuspension, and loss of mature reef structures. Case studies from Indonesia, Malaysia, and Timor-Leste demonstrate both the vulnerability of known wrecks and the growing risk that unlocated sites may be looted before documentation or protection is possible. Full article

Potentially Polluting Wrecks (PPWs) represent a critical global threat to marine ecosystems, requiring proactive risk management aligned with the Precautionary Approach of international environmental law. However, standard multi-criteria risk assessment frameworks frequently suffer from sensitivity to criterion weights, where maximum point allocations determine the relative contributions of criteria to final risk scores. The consequences of these allocations for management classifications require explicit examination. To examine this sensitivity, this study presents a data-driven diagnostic framework integrating machine learning diagnostics with multi-way sensitivity simulations, applied to a comprehensive national fleet dataset ($n=1196$) with targeted diagnostics on the dominant fishing vessel cohort ($n=926$). Unsupervised clustering and supervised architectures (Decision Tree, Random Forest, and Logistic Regression) were deployed to evaluate parameter discriminative power and fleet stratification. The diagnostics revealed that Marine Environmental Sensitivity ($\mathrm{C}5$) has a strong association with the composite score and sensitivity-based classifications. Through bivariate simulations, target-reduction scenarios were identified within a predefined search grid. The illustrative scenario ($\mathrm{S}3$)—applying a $20.0\%$ weight reduction in environmental sensitivity with proportional redistribution—reduced the managed count from $247$ to $167$; fishing vessels comprised $71.60\%$ of the $81$ excluded vessels. This framework quantifies how criterion weighting and redistribution shape management classifications, providing a transparent basis for reviewing priorities within the existing shipwreck assessment system. Full article

This paper (re)construes the remains of a bulk timber carrier called Optimist that reportedly wrecked in the port of Greenville, Liberia during the Liberian civil wars (1989–2003). Its monstrous hull is an uncanny reminder of militarization, industrialization, and deterioration through extractive industries and global regimes of resource exploitation. This unique wreck site illustrates how landscapes created by ruin, abandonment, rust, and decay, especially when associated with times of mass conflict and violence, force us to rethink the meaning of materiality when it comes to modern metal shipwrecks in postconflict contexts. Through the lens of three monsters—skeletons, zombies, and ghosts—this paper suggests that a single, disarticulated wreck can shed light on bigger issues like memory, violence, the future, and archaeological practice in such shipwreck graveyards. Optimist demonstrates how shipwreck graveyards are not only final resting places for exhausted ships but are also conceptual spaces where human emotions like despair, hope, and fear are materialized through ghost stories, local lore, attempts to manage undead and threatening pasts, and material remains of the skeletons of ships past. Full article

Ceramic artifacts excavated from the Nanhai No. 1 shipwreck exhibit dense iron sediments that are mechanically interlocked with the glaze, posing significant challenges for traditional corrosive chemical cleaning. Here, we engineered a near-neutral physicochemical synergistic cleaning system utilizing Micro-Nano Bubbles (MNBs) water and monoethanolamine (MEA)-activated thiourea dioxide (TDO). This work enables near-neutral TDO activation to circumvent alkaline-induced glaze corrosion, while broadening the utility of MNBs from conventional desalination to the physicochemical removal of recalcitrant iron sediments. Multi-scale characterizations, including NTA, EPR, XRD, ICP-OES, and SEM-EDS, were employed to optimize formulations, elucidate mechanisms, and validate efficacy on authentic shards. Results indicated that the optimal formulation (2 wt% TDO/0.1 wt% MEA) maintained safe operating range pH (6.0–8.0) over 3 h. Mechanistically, MEA activated TDO to generate reactive radicals, driving the efficient reductive dissolution of Fe(III) oxides. Crucially, MNBs collapse-induced micro-turbulence significantly enhanced mass transfer into rust fissures, increasing total iron dissolution by 19.7% compared to conventional aqueous solutions. Application on authentic artifacts successfully eradicated Iron Sediments with the glaze integrity well preserved. Ultimately, this facile and highly effective strategy provides a minimally destructive technological framework for the broad conservation and subsequent utilization of underwater cultural heritage. Full article

The XRF, Raman, and fluorescence signatures of approximately fifteen blue-and-white and white porcelain sherds are compared. The assemblage comprises fourteenth- to sixteenth-century porcelain sherds, including Yuan and Ming wares from the Jingdezhen kiln sites, fifteenth- to sixteenth-century wares from the Yuxi and Jianshui kiln sites in Yunnan (China), and Vietnamese sherds comparable to ceramics recovered from the Cu Lao Cham (Hoi An) shipwreck preserved in private collections. Particular attention is paid to the XRF signals of impurities associated with sands (Zr, Y), fluxes (Rb, Sr), and cobalt-bearing ores (As, Mn, Fe, Ni, Bi), as well as to the Raman identification of specific phases in Chinese and Vietnamese porcelains. The similarity between Yunnan and Vietnamese blue-and-white wares is confirmed, notably by their high zirconium concentrations, whereas rubidium concentrations provide a means of distinguishing between the two regions. Overall, XRF signatures enable the non-invasive classification of the sherds according to their material characteristics. The resulting classifications are based on visualizations of clusters in the elemental compositional data using selected elements relevant to geological provenance and ceramic processing. These classifications are then compared with those obtained using PCA and hierarchical clustering based on Euclidean distances. Raman spectra highlight the presence of specific phases, including calcium silicates and phosphates. For the first time, particular emphasis is placed on the importance of considering the entire optical fluorescence spectrum as an identification tool. Special attention is given to the chromium fluorescence doublet with the α-alumina phase formed during the transformation from 2:1 mullite to 3:2 mullite at temperatures above 1200–1250 °C. Full article

A rare carved lacquer (tixi) plate recovered from the Southern Song Dynasty Nanhai No. 1 shipwreck was examined to reconstruct its coating stratigraphy, raw materials, and manufacturing sequence. Detached fragments collected before conservation treatment were investigated by cross-sectional optical microscopy, micro-Raman spectroscopy, thermally assisted hydrolysis–methylation pyrolysis–gas chromatography/mass spectrometry (THM-Py-GC/MS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and wood-anatomical microscopy. The polished cross-section contains nine lacquer layers with a combined thickness of 387.3 μm above a heterogeneous ground, yielding ten visually distinguishable strata. Alternating dark, red, and yellow layers establish the technological basis for the carved polychrome effect. Raman bands identify cinnabar (HgS) in the red layer and orpiment (As₂S₃) in the yellow layer. THM-Py-GC/MS detected homologous alkenes, alkanes, and alkylbenzenes diagnostic of Chinese lacquer derived from Toxicodendron vernicifluum. Monocarboxylic acids were present, whereas no clear dicarboxylic-acid markers of a drying oil were observed; because the object was waterlogged and degraded, this absence is treated as a lack of positive evidence rather than proof that oil was never used. The ground is enriched in Ca and P and is therefore consistent with a bone-ash-based filler, although phase-specific confirmation remains necessary. Wood anatomy identifies the substrate as Chinese fir (Cunninghamia lanceolata, Cupressaceae). Together, the results document an organic–inorganic multilayer coating system and provide material evidence for Southern Song carved-lacquer technology, while defining conservation risks associated with a waterlogged wooden core and light-sensitive pigments. The marine archaeological context and the support-to-surface, layer-resolved design distinguish this case from most previous studies of Song-dynasty lacquerware. Beyond technological reconstruction, the findings identify conservation priorities for waterlogged wood, the wood–ground–lacquer interface, and light-sensitive pigmented layers, and provide a transferable evidence framework for comparative research on archaeological lacquer. Full article

The identification of visible submerged hazards, including shallow-water shipwrecks and associated debris, is important for maritime safety, coastal management, environmental monitoring, and marine archeology. The scope is restricted to wrecks that remain optically visible from above in shallow or intertidal water. This study presents Submerged Hazard Identification and Processing using Augmented Image-based Detection (SHIP-AID), a modular GeoAI evaluation framework for high-resolution RGB imagery. Following site-level quality control, the independent source dataset contains 695 images from 403 wreck sites. The dedicated group-disjoint holdout contains 150 images from 88 sites and 184 annotated wreck objects. Five detector backbones and one task-aware underwater-enhancement baseline were evaluated using ten matched training seeds. Under the standard benchmark evaluation protocol, in which precision and recall are reported at the internally determined maximum-F1 point of the confidence sweep, the best configuration achieved precision 0.896, recall 0.861, mAP@50 0.927, and mAP@50–95 0.668 on the locked holdout. At the fixed, validation-selected operating threshold of 0.45, the primary detector produced threshold-specific precision 0.922 and recall 0.837. Site-clustered bootstrap intervals were 0.895–0.951 for mAP@50 and 0.625–0.704 for mAP@50–95. Physically informed attenuation and backscatter augmentation improved stricter-IoU performance relative to generic augmentation, whereas global Otsu thresholding reduced recall and localization accuracy. Performance remained stable under mild degradation, declined under moderate and strong degradation, and became unreliable under severe low visibility. SHIP-AID is therefore positioned as a decision-support framework for prioritizing optically visible shallow-water sites, with sonar, diving, hydrographic, or archeological evidence retained as the confirmation standard. Full article

The search and discovery of underwater shipwreck sites represent the most arduous and critical phases of underwater archaeology. Wooden shipwrecks, in particular, are characterized by low acoustic impedance contrast and weak magnetic anomalies, coupled with their limited physical dimensions. Consequently, they predominantly exist as shallow-buried, discontinuous small targets scattered within confined areas, making their detection exceptionally challenging. Furthermore, the complexity of the submarine environment—including rugged topography, turbid water columns, and strong currents—poses formidable obstacles to the effective detection of these archaeological remains. Single geophysical methods are often limited by insufficient imaging resolution, interpretation ambiguity, and geological noise, making precise localization and characterization difficult. Focusing on the Nan’ao I Ming Dynasty shipwreck located in waters approximately 24 m deep off the coast of Nan’ao, Guangdong Province, China, this study proposes and validates an “acoustic-magnetic” multi-source data integration detection method. This approach systematically integrates high-resolution multibeam echo sounding (MBES), side-scan sonar (SSS), sub-bottom profiling (SBP), and marine magnetic data to establish a comprehensive framework for identification and integration analysis. The results indicate that the MBES bathymetric data reveal a regular, elongated structure oriented north–south (approximately 34 m × 12 m), closely matching the main hull and deck configuration. The SSS imagery exhibited high backscatter intensity and parallel linear textures, effectively delineating the hard shipwreck structure and the associated rigid protective frame employed for in situ preservation. SBP data confirmed the semi-buried state of the shipwreck (burial depth of approximately 0.6 m). Spatial variations in sediment thickness around the site suggested ongoing modification by strong hydrodynamic processes. Marine magnetic surveys identified localized negative anomalies (−210 nT relative to the ambient magnetic field), contrasting sharply with the positive anomalies of the surrounding natural reefs, thereby indicating an artificial ferromagnetic source. The spatial registration and feature superposition of multi-source data facilitated the characterization of the shipwreck, demonstrating its potential to mitigate environmental interference and enhance detection reliability in this complex environment. Using the Nan’ao I shipwreck site as a case study, this study provides a detailed characterization of the site’s 3D morphology, burial state, and physical properties. The proposed methodology offers a practical and robust technical solution for underwater shipwreck archaeology in complex nearshore environments, providing significant implications for proactive discovery, efficient investigation, and protection of underwater cultural heritage (UCH). Full article

In November 1916, the Imperial German Navy conducted an ambitious raid against the Russian forces in the Baltic Sea. With the aim of attacking Russian ships in the coastal waters of Estonia, a squadron was dispatched from Libau. The operation proved to be very costly, with seven ships sunk by Russian mines and only minimal damage caused to the port of Paldiski. In 2025, the Estonian Maritime Museum conducted a survey of three of the seven Imperial German Navy large torpedo boats sunk north of Hiiumaa island in Estonia. The aim was to identify the wrecks and determine the potential threat the wrecks may pose to the environment from the fuel oil the boats carried. The assessment was time critical as the wrecks had sunk more than a hundred years ago, and due to the location, any oil spill from the wrecks could potentially impact Estonia, Finland, and/or Sweden. The research concluded that all three surveyed wrecks could still contain substantial amounts of fuel oil, and although the wrecks are not leaking and the collapse of the wrecks is not considered imminent, the risk mitigation should be carried out as soon as possible; the possibility for successful oil removal diminishes every year as the wrecks corrode and disintegrate. Full article

The preservation of submerged cultural heritage depends on the ability to locate, document, and monitor sites before they are degraded or lost. Although the North American Great Lakes contain thousands of exceptionally well-preserved shipwrecks, their large geographic extent and diverse operating environments present significant challenges for efficient archeological survey. This study presents a multi-platform autonomous survey framework developed and implemented during 2021–2022 field campaigns in Lake Michigan and Lake Ontario. The framework integrates autonomous underwater vehicles (AUVs), autonomous surface vehicles (ASVs), crewed vessels, side-scan sonar, multibeam bathymetry, magnetometry, optical imaging, and field-based data review within a hierarchical workflow comprising wide-area assessment (WAA) reconnaissance, high-resolution geophysical (HRG) mapping, adaptive mission refinement, and visual confirmation. The surveys produced 19.72 km² of geophysical coverage, including side-scan sonar mosaics, bathymetric surfaces, magnetic anomaly maps, and optical imagery that supported archeological interpretation. A case study from Lake Ontario demonstrates the framework’s effectiveness through the confirmation of a previously undocumented wooden shipwreck using complementary acoustic, magnetic, and visual datasets. Beyond the individual discoveries, the results demonstrate how integrated autonomous systems improve survey efficiency, support adaptive decision-making, and provide scalable methods for digital documentation, baseline site characterization, long-term monitoring, and preservation of submerged cultural heritage in freshwater and marine environments. Full article

The Makara, a potent hybrid guardian figure from Indian architectural sculpture, poses a question for the study of artistic exchange: how did this complex motif travel across Asia and transform into a simplified painted emblem on Chinese export ceramics? We address this question by analyzing a corpus of textual sources, sculptural reliefs, and ceramic assemblages, with a focused case study on ninth-century Changsha kiln production and the pivotal evidence from the Belitung shipwreck. The analysis reveals a profound morphological and functional shift. In stone, the Makara appears as a powerful, three-dimensional guardian in complex crocodilian or elephantine forms. In contrast, on mass-produced Changsha bowls, it is abbreviated to a stylized, two-dimensional head, often paired with a pearl. We argue that this transformation was not a simple degradation but a sophisticated act of modular translation. The shift in medium from stone carving to swift underglaze painting and the demands of a global market forced a functional reinvention: the static, architectural guardian became a portable, commercial emblem. Ultimately, the analysis frames the Changsha artisan as an active cultural translator and the Makara bowls as an early, successful example of customized export design for a global audience. Full article

The accumulation of shipwrecked wood in coastal ecosystems represents an important environmental challenge due to its effects on coastal dynamics, ecosystem functioning, and waste management. The valorization of this lignocellulosic residue through thermochemical conversion offers a sustainable alternative for transforming an underutilized biomass into value-added products. This study evaluated the potential of biochar produced from shipwrecked wood collected in the Punta Roca sector, municipality of Puerto Colombia (Atlántico), as an organic soil amendment. The methodology included the physicochemical characterization of the biochar, as well as analysis of its specific surface area (BET), morphology (SEM), and elemental composition (EDAX). Among the most relevant physicochemical results, the biochar exhibited an organic matter content of 87.85%, an alkaline pH of 10.29, and low moisture content (9.21%), suggesting stability and the capacity to modify soil acidity. Regarding specific surface area, the BET area increased significantly from 0.77 m²/g in untreated wood to 61.61 m²/g in the biochar, indicating a notable enhancement in adsorption capacity. Porosity analysis revealed a decrease in pore size, which may favor the retention of nutrients and water. Elemental composition analysis revealed a high carbon content (82.65%) and oxygen content (15.32%), accompanied by trace amounts of elements such as Na, Mg, Si, Cl, K, and Ca. These results confirm that biochar derived from shipwrecked wood possesses physicochemical characteristics suitable for application as an organic amendment in agricultural soils. Overall, these findings demonstrate that biochar derived from shipwrecked wood is a promising alternative not only as an organic soil amendment but also as a strategy for coastal waste valorization, the promotion of circular economy principles, and the development of more sustainable agricultural systems. Full article

Autonomous Underwater Vehicles (AUVs) equipped with multibeam echosounders (MBESs) are deployed in oceans in expeditions worldwide to find shipwrecks, as they can survey the seafloor at the resolution required to identify such objects. Due to the severely constrained acoustic bandwidth of underwater communication, it is fundamental to transmit compressed information between the AUV and the support vessel when objects of interest are detected during a mission. This paper presents a systematic evaluation of six YOLO-based configurations combining three architectures with two optimizers, along with selected hyperparameters and bathymetric visualization methods, to identify the optimal model for shipwreck detection suitable for deployment on a deep-water AUV. Such an application has the potential to optimize mapping operations, allowing the mission to be terminated early or to employ adaptive route replanning to maximize survey efficiency. We developed and evaluated an object detection model trained on high-resolution shallow-water open-source data, identifying over 630 shipwrecks along the coast of England to fine-tune the model. Six experiments were conducted and compared across the three most recent YOLO architectures by Ultralytics (v8, v11, v26) and specific hyperparameter configurations. The best-performing model achieved scores above 0.91 in precision, recall, F1, and mAP50, while successfully detecting all prominent shipwrecks in the dataset. Three additional models trained on different data visualizations (hillshade, color scale, shaded relief) demonstrated similar performance. The best-performing model was further tested on a small AUV dataset from the Gulf of America, where it successfully detected the shipwreck in deep-water. Full article

Gray siliceous concretions represent the most ubiquitous surface deposits on marine-excavated ceramics from the Nanhai No. 1 shipwreck. These concretions obscure decorative motifs and glaze surfaces of the artifacts, posing challenges to archeological interpretation and heritage conservation. This study conducted a multi-technique characterization of one representative gray siliceous concretion using micro-CT, PLM, SEM-EDS, XRD, FTIR, and micro-Raman spectroscopy. The concretion exhibits distinct three-tier density stratification and consists of quartz, muscovite, calcite, pyrite, and Mg-rich authigenic silicates (serpentine and talc), with quartz and muscovite as the dominant crystalline phases. Its mineral components are inferred to originate from terrigenous clastic, biogenic, and authigenic sources. This work provides fundamental mineralogical data to support the development of targeted conservation strategies for analogous marine-excavated ceramic heritage. Full article