Right-angled fence

Weight

1.9 t

Armor

0 MJ

Toughness

1 MJ

Density

1,521 kg/m³ · sinks

Cost

10

Size

1 × 1 × 1 cells

Armor is taken off every blast that reaches the block; toughness is the damage it takes before it is destroyed. Water is 1,025 kg/m³: denser blocks sink, lighter ones keep the ship afloat. Complexity is the part's share of a ship's 65,535-triangle limit.