[sblock="Placement"]
Fastest way up on deck is probably to climb the fallen mast or the sails (both of which are covered in ice and may be tough to climb; on the other hand, there's lots of fallen rigging draped over to them, so there are plenty of handholds).
I just realized that Murphy's location puts him either underneath the sail, on the opposite side from where Shorrin would prefer to be, or standing on top of it already. To climb up the sail you'll need to take an action in combat, so I've taken the liberty of moving him NW 1 square to the base of the sail (P13), with Shorrin just behind him at M14).
Since nobody objected, I've left Janus's sled off the map (it's 2 squares to the right of X3), but put Shorrin and Murphy's nearby at O15.
[/sblock]
Shorrin and Murphy stare at the three dead men approaching slowly over the ice. How did they get so close? Now that they've seen them they can clearly hear their harsh gasping "breath". How did they miss it before? Two of the zombies look have lifeless, grey skin and eyes, but the center zombie's skin sparkles with frost and it crackles as it moves, and it's eyes are alight with blue flame and hatred.
On the other side of the ship, three zombies have emerged noiselessly from behind the rocks and come face to face with Janus and Larinza! Again, one is covered with frost, and from this distance they can almost feel it sucking the heat from their limbs.
Inside the hold, the zombie that faces Balth struggles to its feet and screams. As it does so, the temperature seems to drop several degrees more.
[sblock="Initiative!"]
Because the zombies are (a) approaching slowly, (b) emerging from behind rocks, and (c) struggling to their feet, you all get a surprise round! (This is to make up for the fact that I had them sneak up on you even though you were alert and watching - it was just for effect.) One standard action each before the zombies get to act, then we start going in initiative order:
Balth (I9) - 27
Chillborn Zombie #1 (P18) - 24
Shorrin (M14) - 18
Zombie #1 (L2) - 17
Chillborn Zombie #2 (M9) - 15
Zombie #2 (O2) - 15
Janus (L5) - 14 (12 when not near Larinza)
Chillborn Zombie #3 (Q4) - 13
Zombie #3 (U16) - 12
Larinza (M4) - 9
Murphy (P13) - 4
Zombie #4 (K19) - -1
[/sblock]
(Backup map)