The Dry Suit

Purple spikes shred my skin,
Sending me into shock as sea
Rushes in to fill me, skin to skin.
Shaking slightly, I ascend,
Seeking sunlite sky--
Slow, sixteen feet to go,
But safety stops my ascent.
Three minutes I stay at sixteen feet
To save me from the chance of DCS.
A swift descent  in a decomp. chamber
Isn't in my schedual for these
Sweet seven days of salvation--
Skiing on the sea, 
Slipping through the ocean's size.
Why didn't I get a semi-dry suit?