A Portrait for Troian - February 7, 1971 - S2-E11
Trivia: "Troian" is the name of series creator Donald P. Bellisario and show producer Deborah Pratt's first daughter.
Another Mother - September 30, 1981 - S2-E13
Trivia: One of the girls mentions wanting to watch "Magnum", as in Magnum P.I. which she ends up doing. Sam replies that the show will be on for 8 more seasons. The episode takes place in 1981, and Magnum P.I. would end its run in 1988. Quantum Leap and Magnum P.I. share a creator, Donald Bellisario.
A Portrait for Troian - February 7, 1971 - S2-E11
Trivia: Show producer Deborah Pratt guest stars in this episode as the title female character. Pratt also voiced "Ziggy" throughout the show's run.
Catch A Falling Star - May 21, 1979 - S2-E10
Trivia: Unlike other episodes which end with a recap, this episode ends with the entire cast and production crew coming on stage and bowing before the audience.
M.I.A. - April 1, 1969 - S2-E22
Trivia: According to the script, Beth really does feel Al dance with her briefly before he leaps, even though he is a hologram. She says his name after he leaps out as an acknowledgement that she knew he was there. This is one of the few episodes we see Al leap instead of Sam.
Her Charm - September 26, 1973 - S2-E15
Trivia: The beginning sequence with the gunfire was shot on the Universal Studios back lot. This same set was better seen in the television show Desperate Housewives. In that show it's known as Wisteria Lane. It is actually Colonial Street and has been used by Universal for over 60 years.
Answer: Sam threw items off the raft to lighten the load, so it wouldn't sink, in doing so he made the raft less heavy. Which made easier to float with the currents, if it was heavy the raft would have moved slower and not moved so far.
Except that Al said that immediately after throwing stuff out of the boat four hours passed and it was shown that they didn't really move from where they were. They were still in the same spot. Forgot to ask this too. When Sam and Vanessa are stranded on the island, one of them, can't remember who, did something and when Al appears, he tells them that because of it, time had suddenly skipped several more hours and if the event hadn't been interrupted, they would have been rescued by a boat. So, what happened on the island that once again caused time to speed up? It seems kind of strange that time could move so quickly on the island, especially since it was still day time and it never showed any sort of changes like the sun or clouds moving.