Motorsailers
the course of preparing this
article, I visited or exchanged
correspondence with more than a
dozen designers, builders, authors,
and publishers—all recognized
experts in the field of yachting—
and came away with a number
of definitions, each unique in its
own way.
• Juan Baader, author of The
Sailing Yacht: “If a yacht is faster
under sail than under power, it is
an auxiliary powered sailboat. On
the other hand, if it is faster under
power than under sail, it is a
motorsailer.”
• Robert Beebe, author of
Voyaging Under Power (note that
these are Beebe’s criteria for a
passagemaker, not specifically a
motorsailer):
1) She may carry sail or not, but
in any case must carry at least
enough fuel for an Atlantic
crossing under power.
2) Her layout and equipment
must be primarily for the comfort
and efficiency of the crew on long passages. In-port
convenience must be secondary.
3) Her seaworthiness, above/below water area ratio
(A/B), ballast, and other factors must clearly mark her
as capable of making long voyages in deep water.
• Dave Gerr, naval architect, director of the
Westlawn Institute of Marine Technology, and author
of The Propeller Handbook, The Nature of Boats, and The
Elements of Boat Strength: “A motorsailer is a boat
which is designed to operate effectively under power
alone, under sail alone, or both combined. Because of
their rigs and keels, they don’t motor as efficiently as
pure powerboats, and because of their large propellers
and relatively heavy engines, they don’t sail as well
as pure sailboats. This created the informal rating
system for motorsailers. You’d have 50/50, 60/40,
or 30/70 motorsailers, and so on. A 50/50 motorsailer
would perform 50 percent as well under power
as a powerboat, and 50 percent as well under sail
as a sailboat.”
• Michael Kasten, naval architect, Kasten Marine
Design: “...a power vessel with a good hull form for
both powering and sailing, with a ‘powerboat-like’
layout and with a modest ‘get-home’ sail rig. There
is little question that a true displacement vessel is
Courtesy of Dave Gerr
Dave Gerr’s drawing of Blue Phoenix shows one possible layout of this twin-keeled
motorsailer, which offers a spacious interior and comfortable pilothouse.
engines, the yachting press started to distinguish
between them and heavier, more powerful boats by
using the term “motorsailer” to describe a cruising
vessel that was able to make efficient progress on
a planned course under sail, by power, or both. The
venerable Rudder magazine of those days developed
a ratio to distinguish the balance between the sailing
and powerboat characteristics of a motorsailer. A
70/30 ratio implied that the yacht worked better as a
sailboat than as a powerboat, a 50/50 ratio indicated
the capabilities were about equal, and a 30/70 ratio
indicated that the boat was a better power cruiser
than sailboat. These ratios became the standard for
defining motorsailers.
If only obtaining the numbers were so easy. I suggest
a visit to www.xente.mundo-r.com/motorsailers/what
_s_.htm, where naval engineer Guillermo Gefaell
presents detailed formulas regarding the technical
characteristics of motorsailers that cover more than
seven single-spaced pages. I am confident that this
mathematical tour de force will satisfy the most
scientific reader.
The question of what makes a boat a motorsailer has
been discussed for many years, with perhaps as many
definitions as there are boats that have been built. Just in
