How to Buy a Sailboat – Part I
Catamarans vs. Monohulls

By Captain David C. Bello

President, Fair Wind Sailing School

Introduction
This article is the fourth of a four part series on the proper process to buy a sailboat.  Unlike most boat purchase advice, written by manufacturers and designed to persuade the reader to purchase one brand or another, the suggestions in this article are written from the perspective of a sailboat buyer and are drawn from the collective wisdom of the author’s dozen or so sailboat purchases as well as conversations with many, many other sailboat buyers. This article will focus on applying the buying process to purchasing an appropriate vessel for heavy air sailing.

The Buying Process
In Part One, we introduced a multi-step process to purchase a sailing vessel.  Our emphasis was on assuring that purchases are based on a detailed description of how and where the vessel would be used and then identifying the best set of vessel characteristics for the specific type of sailing to be completed.  We also introduced vessel characteristics to be considered in the purchase (Table One).  In this article, we examine the relative advantages and disadvantages of cruising catamarans versus monohulls.   
 
Cruising Catamaran Advantages
Charter in the Abacos, Virgin Islands or Grenadines and you are likely to see a rapidly increasing number of cruising catamarans.  The same trend is occurring in many other popular sailing destinations too.  Why are cruising catamarans so rapidly gaining in popularity?  Cats offer many advantages in the most popular chartering grounds.  For starters, the shallow draft of the typical cruising cat opens the door to an expanded number of anchorages.  Since cats gain stability from their wide beams rather than their keel depth, they can offer shallow drafts without sacrificing stability.  For most popular cruising grounds, shallow draft is a big advantage.  Next, cats sail flat.  A heel angle of zero-five degrees is the norm on a large cruising cat, versus ten to twenty degrees for a comparable monohull.  For many sailors, particularly new sailors, the ability to sail flat is a major comfort driver.  Next, in most of these popular chartering areas, the sailing is short, with typical passages of no more than 5-10 nautical miles.  Moreover, the trip between anchorages is often off the wind – with short reaches back and forth between the most popular anchorages.  Again, cats excel in these conditions, with high speeds off the wind.  Finally, the layout of the catamaran lends itself to chartering.  A 45 foot cat will have four staterooms, each with a queen size berth and a private head.  Few, if any, similarly sized monohulls can offer the same level of comfort and privacy. For charterers, and other large groups, the ability to have some privacy – and a private head – can be a “make or break” factor for a good trip.

 Finally, the wide beam of the cat gives it a large aft deck.  A typical 45 foot cat will have a deck/cockpit 24 feet wide by 15 feet deep – perfect for boats that spend the majority of time at anchor with swimming, grilling and socializing the primary use. Therefore, the popularity of cruising catamarans in the chartering industry is driven by the sailing conditions in the popular chartering grounds; specifically short sails across the wind to shallow anchorages. (Table Two)

Monohull Advantages
While cats are gaining in popularity in the chartering world, monohulls continue to offer many advantageous sailing characteristics.  First, monohulls typically offer a much better ride upwind.  The single hull goes through the water better and drives through waves more efficiently than the 2 hulled vessels, providing a more comfortable ride with less pounding through the waves.  In addition, while cats sail fast off the wind, the combination of wider sailing angles and wave pounding slow cats so significantly upwind that monohulls typically make better VMG into the wind.  For those who will be doing a regularly portion of their sailing upwind, monohulls are favored.
Next, monohulls are the choice whenever close-quarters maneuvering is required.  A fin keel monohull can pivot on its keel allowing for a tight turning radius and excellent maneuverability.  Cats, without the keel, must turn through the water and have a much wider turning radius.  Therefore, when tight maneuvering is needed, monohulls are the way to go.  A similar consideration is dock space.  As difficult as it may be to find dock space for a monohull, finding suitable docking locations for a cat – with twice the beam for a given length – can be next to impossible in places like the Chesapeake Bay and Florida.   In addition, even when suitable dock space can be secured, it is likely to be very expensive.   

Another advantage to monohulls is storage space.  While cats provide ample living space, there can be very little space for sailing gear, provisions, safety equipment and tools.   While a typical charter guest may not be concerned with this issue, extended cruisers are acutely aware of this need.  Again, for extended sailing trips the monohull often has much more storage space for essential repair and safety gear than a cat of similar length.

TABLE ONE – BOAT CHARACTERISTICS AND
BOAT DESIGN CONSIDERATIONS

TABLE TWO --
CONDITIONS FAVORING CATS VS MONOS

Summary
Cruising catamarans have become the rage of the Caribbean charter industry because they meet the demands of most charterers very well.  For short hops across relatively protected water, lots of time at anchor, off wind sailing and shallow anchorages, catamarans excel.  The shallow draft, wide beam and berth layout in the typical cruising cat is also perfect for large chartering groups, as is the stability and comfort provided by the wide beam is perfect. 

If upwind sailing will be a component of your normal route, a monohull may be the better option since they sail closer to the wind and move through waves more efficiently.  Monohulls are also the choice when dock space is difficult to secure or maneuverability is tight.  Finally, for extended cruising, the extra storage space provided in the typical monohull has many advantages.