I strongly prefer a keel stepped mast for offshore work.
The bigger stump reason is the most common one but the real reason is that the mast is better supported in the first place.
A keel stepped mast has independent support from the step to the partners to limit movement and takes some loading off the shrouds rather than the end supported column of a deck stepped mast. I've been in the situation of losing the windward shroud and with keel stepping it's possible to pop the sheets and switch tacks to save the stick which we did.
If the mast were deck stepped it would have gone over the side- game over. (BTDT too)
Also a "drogue" on the side of a boat in big seas would probably be bad news as it'd bring the boat beam on to the waves- so hanging on to the rigging most likely wouldn't be a good option.
If the weather is bad enough that significant water is coming in through the sheave boxes, trust me, you'll be otherwise occupied.
Last edited by cormeum; 12-24-2009 at 11:04 AM.