Question

What were the principal travel impulses of such early sea explorers?

Answer 1

Sea explorations were made by many countries centuries ago. These were headed by the European countries long back. The impulses or urges that influenced the explorers are to desire to take hold of other land for territorial expansion. 

Another very important thing to consider as well was the trading. One country had to exchange products to another country. Hence, there were need for them to cross the seas.