1) Scurvy: Scurvy is a disease caused by a deficiency of vitamin C and was a major problem for European explorers who spent long periods at sea. Sailors often developed scurvy after months without fresh fruits or vegetables, and the disease could lead to weakness, fatigue, bleeding, and eventually death.
2) Bad hygiene and disease: European explorers often brought diseases with them to the New World, such as smallpox, measles, and influenza, which devastated native populations who had no immunity to these diseases. Additionally, the lack of hygiene on ships and in new settlements led to the spread of diseases such as typhus, dysentery, and malaria.
3) Unpredictable winds and currents: Sailing ships were heavily reliant on the wind and currents, which could be unpredictable and dangerous. Explorers had to carefully plan their routes to take advantage of favorable winds, and could be delayed for weeks or even months if they encountered unfavorable conditions.
4) Lack of maps and navigational tools: European explorers often had to rely on rudimentary maps and navigational tools, such as the astrolabe and the quadrant, to find their way. This led to many errors and miscalculations, and some explorers even became lost at sea.