{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T19:26:07Z","timestamp":1764962767289,"version":"3.46.0"},"reference-count":34,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T00:00:00Z","timestamp":1764892800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"USRA funding at Cleveland State University, USA"},{"name":"McNair Scholars Program"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Underwater wireless networking is an emerging field for exploration and monitoring, enabling real-time data transmission and communication with both static sensors and submersibles. Current approaches mostly focus on utilizing acoustic waves. The use of optics for this purpose has been known to have several implementation challenges that have prevented it from being considered as a universal alternative. This study proposes that utilizing optics in an adaptive relay wireless network configuration can overcome its primary limitation of line-of-sight (LOS) propagation. In this paper, a network of strategically placed sensors is experimentally constructed with the ability to read and send modulated blue light, fit for extended submersion in water. This proposal represents a hypothetical aquatic drone swarm that is developed and programmed to follow adaptive relay logic. This network is able to demonstrate adaptation to obstructions in the LOS and maintain communication through configurations in which the sender and intended recipient would otherwise be unable to directly communicate. This finding allows the advantages of optical communications to be further explored for aquatic applications, primarily its higher potential data rate, which is inherently productive to a swarm.<\/jats:p>","DOI":"10.3390\/s25247412","type":"journal-article","created":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T18:42:02Z","timestamp":1764960122000},"page":"7412","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Adaptive Relay Free Space Networking for Autonomous Underwater Drone Swarms"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-6386-424X","authenticated-orcid":false,"given":"David","family":"Stack","sequence":"first","affiliation":[{"name":"Washkewicz College of Engineering, Cleveland State University, Cleveland, OH 44115, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Douglas","family":"Nuti","sequence":"additional","affiliation":[{"name":"Washkewicz College of Engineering, Cleveland State University, Cleveland, OH 44115, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9012-3079","authenticated-orcid":false,"given":"Mehdi","family":"Rahmati","sequence":"additional","affiliation":[{"name":"Washkewicz College of Engineering, Cleveland State University, Cleveland, OH 44115, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"eabd8668","DOI":"10.1126\/scirobotics.abd8668","article-title":"Implicit coordination for 3D underwater collective behaviors in a fish-inspired robot swarm","volume":"6","author":"Berlinger","year":"2021","journal-title":"Sci. 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