Yacht Masts: Keel or Deck Stepped?

Many a discussion has been had about the pros and cons of keel or deck stepped masts. There is no doubt that larger yachts will have a keel stepped mast and that racing yachts have a mast tuning advantage with a keel stepped mast. But what are the advantages and disadvantages of keel versus deck stepped masts?

Keel Stepped Masts

This is considered to be a stonger setup. The tension of the rigging rests on the keel and there is extra support to the mast where it passes through the deck. In the event of rigging failure there is more chance that the mast will stay in place.

The main downside is that there is a hole in the deck which has to be sealed against leaking. If you are unfortunate enough to lose the mast whilst at sea there is a hole in the deck, possibly made bigger by the falling mast.

The mast step, out of sight in the bilge, can be prone to corrosion.
Tie rods must be fitted to counteract the pull of halyard turning blocks fitted to the deck around the mast.

Deck Stepped Masts

No hole is required in the deck so there won’t be any issues with water leaking into the boat.

On the downside, it’s a mechanically weaker set up. No real extra room is gained below as a compression post is required to carry the mast load down to the keel. Electrical connections usually exit the mast above deck and so are exposed to the elements.

Rigging Differences between Cruising Yachts and Racing Yachts

Cruising yachts usually have a deck stepped mast with 1 or 2 sets of spreaders. Mast head rigs are more common and they have a heavier, stiffer mast.

Racing yachts and fast cruisers usually have a keel stepped mast and 2 or more sets of spreaders.

The increasing use of deck stepped masts in cruising yachts seems to stem from the following reasons:

• less maintainance as there is no issue with leaking mast boots
• no need to keep an eye on the mast step in the bilge
• interior cosmetic considerations
• easier and cheaper to ship mass produced boats out of the factory completely finished with a neatly a sealed mast step bolted to the deck ready for the mast to be quickly and easily stepped at the point of commissioning

However as long as the maststep and compression post are adequately engineered, the overall strength and suitability of a deck stepped mast is only slightly less than a keel stepped mast. So for the majority of yachts a deck stepped mast will be just fine. For the few pushing their boats hard or often sailing in hard punishing conditions then a keel stepped mast could be the only option.