Groups of logs that are lashed together for transportation over water?

Groups of logs lashed together for transportation over water are commonly referred to as "log rafts" or "log booms." These structures are used to facilitate the movement of timber from logging sites to processing facilities or markets. By bundling logs together, they can float more efficiently and are easier to maneuver on waterways. Log rafts have been an essential method in the timber industry, especially in regions with extensive river systems.