I am trying to discover if there is historical precedent for large naval constructions such as ships or platforms being made largely out of bamboo, to see if it would be practical to do so in the future. So far, all I have found was the bamboo raft making of the Polynesians, which I believe were relatively small and open designs. But I didn't find anything about them building large vessels. Any help or information would be appreciated.
In Qing China, Bamboo culms were built up into large rafts which could exceed 30m in length. These rafts were then floated downriver to urban markets to be broken up for processing or sale.
Bamboo is not as watertight as most wood and becomes waterlogged over time, which is why even small rafts have a working life of only 2-3 years, even if taken out of the water regularly. Some bamboo has a solid culm and could presumably be sawn into boards but I've never seen any evidence that these varieties are any more suited to shipbuilding.
These inferior qualities of Bamboo for shipbuilding were ignored in the case of rafts because:
They were only in the water a short period of time
The rafts needed minimal manueverability
the bamboo itself was the product, so it didn't need to support/hold other cargo
the vessel was exposed only to gentle river currents, not ocean swells