Alvin and the chipmunks are back again in a fascinating movie. This movie happens on a cruise. The chipmunks and Dave have set sea and Dave has to continue to talk to the chipmunks about behaving and not getting themselves into trouble. Of course Alvin loves being a little on the dangerous side. One of his attempts at being "dangerous" leads Dave to make the chipmunks stay on the upper deck while he can finally take a breath! Well, Alvin sparks an idea to play with the end of a kite to see the whole ship from a bird's eye view in the sky. Little behold all of the chipmunks become involved with this kite activity and the wind sweeps the kite off the ship with the chipmunks holding on. They become shipwrecked on an island thought to be deserted. They soon find out they are not deserted. There is a crazy lady with fruit as friends.
In a panic Dave fell off the ship to save his chipmunks. It turns up his "pal" Ian is also on the cruise disguised in a pelican uniform. Not only had Ian previously tried to be the manager of the chipmunks he tried to be the manager of the chipettes as well .He too went off the side of the ship after a confrontation with Dave about a piece of equipment that could save the chipmunks from having to be on the "deserted" island.
Now Dave must try to find his chipmunks with this obnoxious man, Ian. As he tries to find them, the movie really throws out at the audience, the true meaning of family and perseverance. Both the chipmunks, Dave and Ian are looking for each other and missing each other often. At the end of the day both "search parties" are exhausted!
By the next morning Dave and the chipmunks continue to look for each other and when they finally do, they are completely ecstatic. The crazy lady on the island is looking for the treasure and she steals one of the chipettes to retrieve that treasure!!! In this fight to get the little chipette back, Dave convinces the lady to release her and shortly after the crazy lady changes her ways and eventually everyone is on their way back to civilization, in this very adventurous movie filled with laughter, sadness, family and lots of singing!