Kayak/Canoe/Boat made of cardboard with tarpauline for water resistance
Very large cardboard boxes, 50mm parcel tape rolls, scissors, saws, tarpaulins, marker pens.
Explain to Young People (YP) they are to draw a design of a boat that will be capable of carrying one or more people, perhaps 6 at a push made out of the cardboard that they can see. The boat needs a name and should be marked up on the vessel with marker pens.
Resources: Cardboard packaging from large items like bicycles, TVs, furniture is a basic requirement and easily sourced from local retailers disposing of it and free. Parcel tape rolls is the only real expense and limit a build to a roll but keep some in reserve. Scissors are useful for cutting but for harder cuts a saw may be helpful, obviously inherent risks so perhaps done by a leader unless one trusts the YP.
Leaders should approve the basic build design prior to building.
Let the YP build for 60-90 minutes and advise if the build needs adjusting adding struts, etc.., but do not assist other than advice.
Groups could be judged/awarded points on build/design/quality.
Final 10/15 minutes tarps should be introduced and added to water proof the boats, this could be done on another night if over running.
Suggested deign below in upload