Two words will inspire kid-fear this summer: Water Mortar
Aside from the pleasing assonance of this product's name, what we like is that it is, in effect, a grenade launcher for water bombs.
With a shoulder rest, loading lever and firing trigger you're never not going to inspire pant-browning fear in the neighbourhood kids.
Load up a water bomb and watch in joy and amazement as this fires it up to eight metres...
£19.99 well spent, link below.