That sounds like challenge!
It was well before affordable radio-control hobby transmitters were available. All of us ( only 7 in the class ) spent hours messing around which guidance systems ( a little wind vane attached to the rudder, a candle that burned down and then burnt through a string holding a rudder in position, etc.) learning to allow for the breeze that blew out of the northwest at certain times of the day (only to be undone by the contest being scheduled for later in the afternoon, went it was windiest). The winner came within fifteen feet of the center point.
Propulsion systems ranging from a mousetrap powered side-wheeler, sails, and electric motors and propellers. I took the path of greatest resistance and devised a linked "crew" of four oarsmen (their bodies were foam rubber) to row across. "We" got blown off course, and ended up pinned to side of the pool by the breeze, but I did get some points for originality.
I think the idea behind these exercises is to reinforce the satisfaction
one gets from the act of conceptualization, goal setting, persistence in execution, and realization
of the end product; and teamwork between designers.
Too much fun...