Thanks John.
The frame is manufactured from plate against plated 5mm and arms are hollow aluminum tube 10mm. Between axis 540mm. I use four engines Keda 1053kv 19A 20.20L with four controller Turnigy 25A. The motherboard is a AQ50D Pro. It integrates video management platform. The boat is aluminum 0.5mm thick. It weighs 1kg300 and can support the weight of a reflex.

The battery is 11.1V 3S 2650Mah for 15/20mn autonomy.

please Anthony can you tell me about propellers and where did you buy it ??