There is no time element. Take your time. Your boats can travel forward and back and even sideways. If an empty bench gets next to a survivor, he will stop the boat and climb on. (Nice graphics.) If 2 passengers are adjacent to the same bench, you get to decide which one to take. Once a boat is full, it cannot move.
So here's the update: this new version has icebergs. The lifeboats can push the icebergs NOT in a sokoban type way. Your boat can push multiple bergs at the same time. Forward, back and sideways.
Of course there are 4 levels of difficulty, but now that's doubled. The Deep Blue levels are the same as the original Titanic. The new ones are called Iceberg. 204 levels - should keep you busy for a while. I skipped the Beginner Iceberg levels and jumped into the junior levels. I did all 24 of those, but must confess, I struggled on some of them. On the Expert Iceberg levels, I've done 7 of the 24. I'd like to think that they are impossible, but that's what makes it very good, right!
Titanic By SmartGames is one of the best puzzle game apps of 2014. Bravo Raf!
By the way, there's an old silent film called Way Down East that's got an incredible scene of a woman jumping among ice floes before she gets to a waterfall.
Titanic is the only puzzle app that I can think of that that stems from an historical event.