Well, that makes absolutely no sense at all
I hadn't seen these films before but there was nothing better on TV so just watched the first film, which is now being followed by the sequel.
At the end of the first film, the three of them are found in the dinghy by Richard's father (far fetched indeed) and when he asks if they are dead, the reply is "no, they are sleeping". This may or may not simply mean "they are dead" but the way sailor adamantly says "no sir, they're sleeping" makes me think not.
End of film.
So now to the start of the sequel.
Another boat, which appears to have nothing to do with Richard's father, has also found the little dinghy the three are on. Now they are dead, apart from the baby.
So - what happened to Richard's father finding them? Did he decide he couldn't be bothered rescuing them after all?
How has the baby aged so much and his hair grown?
How did they manage to not only change positions in the dinghy, but also change the dinghy itself?
Did the director of the sequel scan through the script of the original and make the rest up as he went along?
I suspect I'm about to give up on this one!