<p>Logboats (monoxyls) dominate the early medieval watercraft records of the southern Baltic and Central European river basins. Within this broad corpus, a small number of unusually long dugout canoes (Circa [c.] 8–10&#xa0;m [m]) from Ostrów Lednicki and Mikulčice share several recurring morphological traits and comparable depositional settings. This article examines whether these similarities justify treating them as a provisional comparative subgroup rather than as isolated large dugouts. The analysis focuses on the best-documented examples from Poland and the Czech Republic. It considers hull proportions, bow and stern form, the presence and arrangement of transverse ridges, wood species, chronology, and archaeological context. The comparison shows repeated features, including elongated proportions, bow arrangements suitable for fastening or mooring, frequent transverse ridges, and stern overhangs. However, the sample remains small and unevenly documented, and some of these similarities may reflect convergent hydrodynamic or practical solutions rather than a distinct boatbuilding tradition. The repeated association of the best-preserved examples with major bridge contexts is noteworthy, but it does not, in itself, prove a specialized engineering function. Instead, it suggests a range of possible uses related to transport, logistics, and infrastructure, while leaving room for other interpretations. The article, therefore, argues not for a formal typology but for the heuristic value of recognizing a small cluster of long monoxyls that merits further comparative study. Future progress depends on enlarged samples, standardizing metric recordings, improved dating, and the integration of use-wear, 3D, and experimental analyses.</p>