8 1/2 Months - November 15, 1955 - S3-E12
Continuity mistake: When Al is talking to Sam in the beginning about having to deliver the baby before he leaps, Sam gives Al a funny look. The scene cuts and instantly Al has a cigar in his mouth. We never see him put it in his mouth.
Disco Inferno - April 1, 1976 - S2-E2
Continuity mistake: Sam is buttoning up his shirt while at the bar. His hands are about halfway down his shirt. Cut and we see him from another angle. His hands are now down.
The Right Hand of God - October 24, 1974 - S1-E4
Continuity mistake: Near the beginning, Sam has a cut on his left eye from the fight which they apply a bandage to later. The cut briefly disappears when Sam is talking to the sister, only to reappear.
Genesis (1) - September 13, 1956 - S1-E1
Continuity mistake: Al is talking to Sam near the hanger about his options regarding the pilot. When we see Sam and the back of Al's head, there is a significant shadow on Al. It isn't there in the opposite angle. On top of that, since Al is a hologram, shadows shouldn't affect him.
Catch A Falling Star - May 21, 1979 - S2-E10
Continuity mistake: The makeup lady puts a moustache on Sam right after he leaps into the man. A stagehand bursts in, telling him it is time to go on. The moustache is now gone, and the makeup lady puts it back on Sam's face.
Piano Man - November 10, 1985 - S3-E15
Continuity mistake: The old Ford pickup Sam steals to chase them is noticeably different than the one we see being driven later, including the front end, side, and roof damage, different side mirror type, no antenna on driven truck, and a different license plate number. (00:35:50)
What Price Gloria? - October 16, 1961 - S2-E4
Continuity mistake: When Sam goes out of the window to save Gloria, part of the ledge breaks off, but in the near shots it is broken off almost to the corner near Gloria, while in the shots from below most of the ledge is still intact. (00:35:45)
Catch A Falling Star - May 21, 1979 - S2-E10
Continuity mistake: When Sam is going on stage near the beginning, another guy peels off his moustache and says "imposter." The problem is, the makeup lady already removed his moustache earlier in the episode.
Leaping of the Shrew - September 27, 1956 - S5-E3
Continuity mistake: The wide shot of the raft shows clear skies but the closeups are all cloudy.
Freedom - November 22, 1970 - S2-E16
Continuity mistake: Sam is talking to Al in the desert about what year it is. Al's cigar jumps in his mouth and back to his hand.
Jimmy - October 14, 1964 - S2-E8
Continuity mistake: Near the end of the episode Michael Madsen's character attempts to run over Sam with a forklift, causing the boy to fall into the water and almost drown. As the boy is falling into the water, there is a wide shot of the action. In the scene, a box is being pushed over the edge into the harbor. In the close shot following, the box is gone, as are other items nearby.
Her Charm - September 26, 1973 - S2-E15
Continuity mistake: The rearview mirror on Nick's car disappears and reappears repeatedly, when he pursues the laundry truck and later at the cabin.
Another Mother - September 30, 1981 - S2-E13
Continuity mistake: When Sam uses martial arts against the men from the van, one of them pulls a knife as he kneels on his right knee in the close-up, but next shot he is kneeling on his left knee.
Another Mother - September 30, 1981 - S2-E13
Continuity mistake: When one of the sicko men from the van pulls a knife on Sam, the white blouse is either tucked into the skirt or hangs over it, depending on the shot.
Play It Again, Seymour - April 14, 1953 - S1-E9
Continuity mistake: The cut on Sam's face from the bullet is larger than the one on his counterpart's face.
The Curse of Ptah-Hotep - March 2, 1957 - S4-E20
Continuity mistake: The size and shape of the hole Sam creates, when he breaks through the wall, is considerably different on the outside than it is on the inside of the burial chamber. (00:20:10)
The Curse of Ptah-Hotep - March 2, 1957 - S4-E20
Continuity mistake: When he starts swinging the pick-ax, Sam's bandanna instantly moves between shots from around his neck to over his face. (00:19:25)
A Portrait for Troian - February 7, 1971 - S2-E11
Continuity mistake: When she's confronting her brother on the dock, Troian's long hair shifts from being completely behind her back to falling over her shoulders in front with each change of camera angle. (00:35:00)
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.