mjm yachts 50z Series User manual

401-862-4367 .
[e-mail]
May 2015
Dear 50z Owner:
Congratulations on becoming Captain and Owner of the world’s best built and most fuel efficient yacht of its size.
This 50z Owner’s Manual should further contribute to your enjoyment and proficiency afloat.
This manual was created jointly with Zurn Yacht Design, Boston BoatWorks and MJM Yachts. Our experience
with the first 190 boats (all models included) has been incorporated to make this manual as useful and relevant
as possible. Keep in mind that there maybe some variances or custom additions to your boat which were installed after
printing of this manual. And, from time-to-time we will change specifications to keep pace with changes made to
improve the boat.
When addressing a problem with a specific piece of equipment, this 50z Owner’s Manual is to be regarded only as a
preliminary source of information. The equipment manufacturer’s own manual with trouble-shooting procedures,
etc. is the primary source and authority. And starting with the 50z , in addition to two large binders with hard copies of
equipment manuals, you will find a CD disc with a digital copies you can access on your computer, carry around with
you and consult when convenient… like when commuting on AMTRAK instead of reading the morning paper.
A Small Craft Owner’s Manual accompanies, and forms part of, this 50z Owner Manual. This booklet has universal
handling and operating tips worth reviewing.
This 50z Owner’s Manual is designed to be a living document, not only for builder updates but for your own use and
record. Each boat is provided with a copy of the current Manual organized in a STAPLES “Mini-Ring” type binder
that allows you to add pages as needed.
One of the great advantages of purchasing a series-built or semi-custom design is that owners have the benefit of
learning from one another. So, with your continued input and comments we can keep adding useful information and
helpful hints to this manual.
Part of the ISO CE Mark Certification Program is confirmation by the owner that the manual has been received.
Please sign the extra page No. 3 included in the Manual as a receipt and return it in the stamped envelope provided.
Best wishes for fair winds and sunny skies. On behalf of the builder and designer, we are most appreciative, and I
am particularly honored, that you have chosen the 50z.
Robert L. Johnstone
Founder & CEO
Note: This manual is published in accordance with ISO standard 10240:1995E Small Craft - Owner’s Manual

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®
50z Owner’s Manual
LOA - Length Overall w/Swim Platform & Bow Roller & Rail 55’ 3”
LOD - Length On Deck 50’ 0”
Beam 15’ 0”
Draft Twin IPS 2’ 11” Triple I/0 3’ 3” Triple IPS 3’ 10”
Displacement – ½Load 32,850 lbs.
Fuel Tankage -Two 260 Gallon Tanks 520 gals.
Fresh Water Tankage – Including Hot Water Tank 170 gals.
Holding Tank w/Macerator Overboard Discharge 30 gals.
Air Height over Water w/Radar Mounted on Hard Top 10’ 6”
Headroom Bridgedeck 7’ 0” Wheel 6’ 4”- 6’ 8” Belowdecks 6’ 4” – 6’ 5”

CE CERTIFICATION
CERTIFICATE NO.
AUTHORITY
ADDRESS
PHONE NUMBER
WEBSITE:
CLASSIFICATION:
CAPACITY
Category A Conditions
Category B Conditions
--------------------------------------------------------------------------------------------------------------------------------------------
RECEIPT BY OWNER In compliance with ISO 10240:1995(E) the owner hereby certifies receipt
of this manual and has read and agrees to the terms of the Builder’s Limited Warranty included herein.
Print Name
Boat Name
City, State, Zip
NOTE: PLEASE SIGN ONE OF THE TWO COPIES OF THIS PAGE AND RETURN IT IN THE
ATTACHED STAMPED ENVELOPE TO: MJM YACHTS at 39 Washington St. Newport RI 02840
Denotes an extreme intrinsic hazard exits which would result in high probability of
death or irreparable injury if proper precautions are not taken.
Denotes a hazard exists which can result in injury or death if proper precautions
are not taken.
Denotes a reminder of safety practices or directs attention to unsafe practices
which could result in personal injury or damage to the craft or components.
International Marine Certification Institute
Rue Abbe Cuypers 3
B-1040 Bruxelles, Belgique
[phone]
ISO CE Mark Design Category A (ISO 12217-1 Stability) for craft
designed for offshore voyages (1) where the vessel is correctly handled
in the sense of good seamanship and operated at a speed appropriate to
the prevailing sea state and (2) with significant wave heights above 4 m
(calculations are based on 7 m) and wind speeds in excess of Beaufort
Force 8, but excluding abnormal conditions, e.g. hurricanes.
Maximum 18 Persons
Maximum 30 Persons
BBBW005
www.imci.org
NAME:
Signature Date
Hull #
ADDRESS:
MOBILE:
EMAIL:

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DIGITAL'LIBRARY'of'MJM'50z'EQUIPMENT'MANUALS'
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1.1
1.2
1.3
1.4
OPERATION
GENERAL
This manual has been compiled to help you operate your yacht with safety and pleasure. It
contains details of the yacht; the equipment supplied or fitted, its systems, and information on its
operation and maintenance. Please read it carefully, and familiarize yourself with the yacht
before using it.
If this is your first yacht, or you are changing to a type of yacht you are not familiar with, for your
own comfort and safety, please insure that you obtain handling and operating instruction and gain
some experience before assuming command of the yacht. Your dealer or yacht club will be
pleased to advise you of local schools, or competent instructors.
PLEASE KEEP THIS MANUAL IN A SECURE PLACE ON THE BOAT, AND HAND IT OVER TO
THE NEW OWNER IF YOU EVER SELL THE CRAFT.
This Owner’s Manual is not intended to be a course in boating safety, boat handling, navigation
or general boating skills. It is the responsibility of the user to independently gain these skills.
Instead, this manual will serve as a reference for matters specific to the 50z. Standard options
are included in the manual with which your particular yacht may or may not be fitted. Custom
options may be addressed in an addendum.
QUICK START GUIDE (See CHAPTER 16)
A separate “Quick Start Guide” is included that briefly reviews the key items to check before
departure. Please review the topics in this manual before relying on the checklist – it is simply an
“at-a-glance” sheet to insure that you don’t overlook anything important.
OPERATING PROCEDURES – ENGINE INSPECTION
To completely access the propulsion system, the cockpit engine hatch must be raised. The
procedure is as follows:
Make sure the side access doors are closed and that personnel and
equipment are clear of any moving parts before operating
- Turn ON house battery rocker switch (located over DC electrical panel)
- Turn ON DC main breaker & engine hatch breaker on the DC panel
- Activate the engine hatch lift with the black toggle switch in the starboard cockpit seat locker.
NAVIGATION
The builder installed navigation equipment includes a compensated Ritchie Compass with
Deviation Card, autopilot w/compass, depth sounder, chart-plotter, and radar. Modern marine
electronics are a subject unto themselves and you should refer to the manuals that came with the
equipment you purchased. However, here are a few points to consider:
+If you are unfamiliar with navigation, educate yourself before using the boat. Electronic
equipment is NOT a substitute for dead-reckoning navigation skills.
+It is not recommended to rely solely on electronic charts- bring Chart Kit paper chart back-ups.
+Get a good iPhone App with Nautical Charts and GPS as a backup.
+Check that all equipment is functioning, even if you intend not to use it.
+Radar and its overlay projection on the plotter should be properly aligned (Double-check
when underway) See manual to adjust, tune and operate.
CHAPTER 1

CHAPTER 1
Compass Heading
There are 3 heading references for navigation on the 50z: (1) The compass on the dash, (2)
Autopilot digital compass, and (3) GPS COG (Course Over Ground). All of these headings should
be within a degree or so of each other when underway. If not, it is recommended that differences
be recorded on a deviation card. Use COG as the primary reference at a time when you are
not influenced by wind/wave/tidal set.
Boat Speed Rather than a paddle wheel or sonic device, the Raymarine C120 plotter is used to
generate SOG (Speed Over Ground) that is displayed by the chart-plotter and may also be
shown in larger digits on the Autopilot display. Eventually, you will learn to approximate boat
speed through the water by relating it to RPM on the tachometer.
1.5 Hauling & Blocking A facility that is unfamiliar with the 50z may require information before
hauling the boat with a Travelift or crane & straps. Refer to the illustration included at the back
of this manual. The keel (centerline of the boat) and chines (edges) should be used to position
weight-bearing supports. You will note that the fore and aft lift points are located
approximately at either end of the pilothouse... e.g. abeam of the windshield and the aft end of
the hard top.
Point loading flat areas other than centerline and chine or setting the
weight of the hull on supports of insufficient area may result in damage to the hull.
OPERATION
Avoid storing steel or iron items such as tools nearby any compass.

2.1
SAFETY EQUIPMENT
GENERAL
Spend time reviewing where your safety equipment is and how it functions BEFORE you need it.
Remember, the best way to protect yourself and others from accidents is to eliminate potential
causes of accidents before they occur. Good seamanship and common sense go a long way in
this endeavor.
Here is a safety checklist derived in part from the USCG Vessel Check List. State Regulations
may vary:
PFD’s
A wearable USCG approved personal flotation device (life-jacket) must be provided for each
person aboard. On the 50z, these can be types I, II, III or V. Also, one type IV throwable PFD
must be immediately available for use.
Children under 13 years of age are required to wear a USCG life jacket that fits when underway
unless they are in an enclosed cabin or belowdecks.
Visual Distress Signals (VDS)
You must carry VDS’s aboard. If operating between sunset and sunrise, they must be suitable for
night use and be within the age dates marked on the side of the flares. A minimum of 3 day/night
use combination pyrotechnic flares are required. For a list of USCG approved devices, see the
USCG recreational checklist.
Fire Extinguisher
In addition to the automatic fire suppression system fitted in the engine space, you are required to
carry at least two type B-1 extinguishers aboard, which are located in the galley and outboard of
the starboard helm seat. This should be checked regularly.
EPIRB
Especially if operating offshore, an EPIRB (electronic position indicating radio beacon) is
recommended.
Ships Papers & Registration
You should carry the vessel’s registration papers and number plate.
Pollution Regulation Plaques
5”x8” Oil Discharge Plaque and a 4”x9” Waste Discharge Placard should be fixed were visible.
Charts & Light Lists
Charts, light lists and a USCG required copy of the Inland “Rules of the Road” Navigation Rules
Horn or Whistle
Recommended to signal intentions or signal position. For instance, when in a narrow channel or
the Intracoastal Waterway: To signal which side of another boat you will pass on, blow 1 blast if
you are passing to their starboard side and 2 blasts if passing on their port side. The Kahlenburg
horn has a repetitive automatic fog signal that can be activated for either underway or at anchor.
Life Raft
If you plan to be coastal cruising out of sight of land, it is prudent to carry a Coastal Life Raft
which come in compact sizes that can be stored in one of the aft cockpit lockers.
Heaving Line
These floating lines are available and handy to have ready in case of emergency or to simply trail
behind the boat when swimming, .with the end attached to one of the stern cleats.
CHAPTER 2