You cower in the bottom of the boat under a tarpaulin and pray they'll miss you.
Why I like this ending
Some death paragraphs, particularly ones by Peter Darvill-Evans are great because they into loads of disgusting detail of how you meet your end. This paragraph is great because it doesn't. All it tells you is that your plan doesn't work and that the result of your choice ends in your death, but it is left to your imagination of just how the phantoms suck out your soul.
The paragraph is almost written like a joke. It describes your "plan" as a build up. The punchline, 'They don't' is a commentary on how lame your plan was.
I think this is Dave Morris's way of saying 'YOU'RE A FREAKING WIZARD. I GAVE YOU 9 SPELLS AT THE BEGINNING OF THE BOOK AND THE BEST YOU CAN DO IS HIDE IN A BOAT. GET STUFFED.'
How did I get into this mess?
I'm a wizard trying to get across a swamp. I meet a ferryman who says that phantoms live in the swamp and eat people's souls, but his boat is blessed and will protect you if you pay him 2 items to get across. That's half the things I can carry. I decide to take another boat for free, but then realise that there are phantoms on the swamp and they want to eat my soul. I have the option of hiding or casting a spell. Casting a spell is the best option.
What have I learnt from this?
A lot of the death endings you read will be because of really stupid choices. There is more than one way of telling someone that they have made a stupid choice than just telling them that their choice was stupid.