Hi...I'm new and have a question...

Hi...I just thought I'd 'kill two birds with one stone'
since I don't have much time before I head off to work.
I'm Kelly...and I'm new to sailing...TOTALLY NEW!
My boyfriend of almost 2 years recently bought a sailboat and has yet to put it in the water as he is waiting for some work to be completed on it.
We're looking forward to getting away on it even though we are now into the colder months!!
I'm sure I will have lots of questions for all of you who are experienced sailors!
In the meantime, I have just one question for now.
My guy mentioned that he would like a knife to use on his boat....for emergency purposes...like having to cut through rope.
I have been asking in a particular store for some info and havent had much time yet to google some info.
The knife I've been looking at is the Spyderco brand.
There are a couple that have been recommended to me and I want to make sure that I get the right kind for him (for Christmas...so I can't ask him!!)
So...which kind would be best?
There is one with a pointed tip and a curved, surrated blade.
And another with a straight edge...surrated blade with a rounded tip.

Some models that I've had mentioned to me by salespeople are the
-spyderhawk salt (C77YL)
-saver (I dont know the model number)
-atlantic salt (SC89SYL)

Which knife do you use?
And do you have any pointers or tips (pardon the pun)
when purchasing a knife for 'pleasure sailing'.
Is a surrated edge better than a razor edge?
Is it better to have a rounded tip...as opposed to a pointed tip?

Thanks for your advice!!