Final answer:
The critical advancement in the first half of the 19th century that transformed global navies was the introduction of steam power. This led to the development of steam engines and steamships like Robert Fulton's Clermont, and significantly influenced military and commercial maritime operations.
Step-by-step explanation:
The pivotal development in naval technology that changed navies worldwide in the first half of the 19th century was the introduction of steam power. This innovation allowed ships to move independently of the wind, leading to faster movement and more reliable navigation. The advent of steam-powered ships was a direct consequence of the Industrial Revolution, which started in the late 1700s and introduced significant changes in production methods, including the use of steam engines for power.
Naval theorist Alfred Mahan highlighted the importance of a modernized navy in his 1890 work, noting the need for faster battleships and global refueling stations, reflecting the strategic significance of technological advancements like steamship engines. The shift to these new technologies was evident in the drastic changes experienced by navies around the world, leading to new classes of ships such as the HMS Dreadnought in 1906, which far outpaced earlier ships in both firepower and speed thanks to steam turbines.
The influence of these technologies went beyond military applications. On a commercial level, steamboats, starting with Robert Fulton's Clermont, revolutionized water transportation by providing faster, cheaper, and more dependable means of moving goods and people, notably stimulating the economic development and westward settlement of the United States.