Wherever sailors gather together for a beer and a gam you’ll hear this discussion: Deck stepped or keel stepped mast for cruising?
One of the benefits of a keel stepped mast for a long distance cruiser is that, in the event of a shroud or stay failing, the deck aperture will probably hold the mast up long enough for you to reduce the load on it. With a deck stepped mast it’s more likely to topple straight over.
But, on the other hand, the deck stepped mast is more likely to remain in one piece and could be recovered to set sail again. The keel stepped mast could break above deck leaving a stub, which may or may not be useful to jury rig a sail. Also, there is the possibility of the collapsing keel stepped mast structurally damaging the coach roof at the aperture.
The keel stepped mast is more likely to leak – mast boots are a pain in the neck. On my ketch I found that the most effective mast aperture sealer was duct tape. Once the deck chocks were set up I’d wrap the whole thing with duct tape and then cover that with the painted canvas decorative boot to improve the aesthetics.
Any leakage into the keel stepped mast through halyard and cable entries will end up in the bilge, but the mast does provide a convenient conduit to get cables below. In the case of a deck stepped mast there is no way to get cabling below without making holes through the coach roof or deck and these can be a source of leaks if not properly protected by a Cableport, swan neck tube or deck glands.
You might think that the deck stepped mast would have the significant advantage of saving space in the cabin but this isn’t necessarily so; a compression post is often needed to take the rig load from the deck stepped mast down to the keel. If the layout of the boat is such that a bulkhead can be advantageously placed directly under the mast step then there probably is a space saving. If that bulkhead has a door in it you’ll need to be careful that rig tension doesn’t distort the coach roof enough to jam the door.
I’ve happily cruised with both arrangements – keel and deck stepped – and can’t say I’d pick one over the other if I were planning a new boat. However, in the case of trailer sailors, or when you cruise in an area that requires you to sail under bridges, a deck stepped, tabernacle mounted mast wins hands down.