Communication in underwater environments is extremely challenging: bandwidth limitation, latency, and extreme packet losses are only the tip of the iceberg. Usually, just a few bytes can be conveyed, and due to the lack of common standards in the physical layer, the problem becomes even more complex. An accurate network architecture, aiming to maximize message portability in different networking scenarios while supporting significantly different transportation and physical layers, becomes mandatory. Thus, a cross-layer approach is proposed, moving some networking and transport details to the application layer while leveraging the publish-subscribe pattern to limit shared resource usage.