The Christian crusades used a number of different routes and often took years to work their way to the "Holy Land." Several of them combined both land and sea routes but it is possible to break down some of them into a majority land or sea routing. The first crusade was mostly overland though a group of crusaders did cross the Adriatic Sea on their way from Italy to Constantinople where the crusaders all met and then moved together as a body to the Holy Land.
The second crusade also traveled mainly by land but when the land route stopped in Antioch there was also a group that traveled by sea to Jerusalem.
The third crusade was mainly by sea with groups coming from England, France and Italy by sea and then converging on Jerusalem with the Fourth Crusade also going by sea from Northern Italy to Constantinople.