I looked up the etymology because I had not idea as to its origin. The "Rover Boys" presumably liked to be constantly on the move, though with no particular destination in mind,just looking for adventure. But no piratical motives, as suggested by last line of definition and etymology.

rover1 ['rəʊvə]
noun
1 a person who roves; wanderer

2 (Archery) a mark selected at random for use as a target

3 (Croquet) a ball that has been driven through all the hoops but has not yet hit the winning peg

4 (Australian Rules football) one of the three players in the ruck, usually smaller than the other two, selected for his agility in play
[ETYMOLOGY: 15th Century: from rove1]


rover2 ['rəʊvə]
noun a pirate or pirate ship
[ETYMOLOGY: 14th Century: probably from Middle Dutch or Middle Low German, from roven to rob]