Which one among the following metals is used for making boats because it does not corrode by seawater?

Titanium is the metal used for making boats and marine equipment because it exhibits exceptional resistance to seawater corrosion. Unlike iron, which rusts when exposed to moisture and air [2], titanium forms a stable, protective oxide film that quickly regenerates if scratched, making it virtually immune to natural seawater. This property, combined with its high strength-to-weight ratio and impact resistance, has earned it the nickname 'marine metal'. While nickel is often alloyed with copper or chromium to improve corrosion resistance in marine environments [4], pure titanium is uniquely suited for hull structural parts and deep-sea pressure hulls due to its ability to achieve a lifespan equal to the marine equipment itself. Tungsten and antimony do not possess the specific combination of lightweight and seawater immunity required for primary boat construction.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 1: Chemical Reactions and Equations > 1.3.1 Corrosion > p. 13
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > 3.5 CORROSION > p. 53
3. [3] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > 3.5.1 Prevention of Corrosion > p. 54
4. [4] https://en.wikipedia.org/wiki/Monel