12.1. General
12.1.1 Section 12.2 defines the requirements for minimum freeboard for a motor vessel
whose stability has not been assessed using ISO 12217footnote (see Appendix 13). Section 12.3 defines how the freeboard
mark and deck line should be applied. Requirements for an inflatable boat or boat fitted
with a buoyant collar, not requiring an approved Stability Information Booklet, are
contained within section 12.4.
12.1.2 It should be noted that vessels whose freeboard is determined using section 12.2
which are not provided with an approved stability information booklet are required to be
marked with a freeboard mark or alternative. In such cases the loading of the vessel is
governed by the maximum permissible weight, in accordance with section 11, as identified
on the vessel’s certificate, or appropriate to the load test at which the heel test was
conducted, or in the condition to which the ISO 12217 is assigned.
12.2 Minimum Freeboard
12.2.1 The freeboard, for a motor vessel whose stability has not been assessed in
conjunction with section 11.4.6, should be not less than that determined by the
following requirements:
12.2.2 The vessel should be operated and freeboard calculated at a normal trim.
12.2.3 Vessels which carry cargo or a combination of passengers, industrial personnel
and cargo for which the cargo element does not exceed 1000kg.
A vessel, other than an inflatable or rigid inflatable boat covered by section 12.5,
when fully loaded with cargo and non-cargo deadweight items certificated to be carried
(each person taken as 82.5kg) should be upright and;
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.1 in the case of a vessel with a continuous watertight weather deck in accordance
with section 4.3.1.1, which is neither stepped or recessed or raised, have a
freeboard measured down from the lowest point of the weather deck of not less than
300 mm for vessels of 7 metres in length or under and not less than 750 mm for
vessels of 18 metres in length or over. For a vessel of intermediate length the
freeboard should be determined by linear interpolation;
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.2 in the case of a vessel with a continuous watertight weather deck in accordance
with section 4.3.1.2, which may be stepped, recessed, or raised, have a freeboard
measured down from the lowest point of the weather deck, of not less than 200mm
for vessels of 7 metres in length or under and not less than 400mm for vessels of
18 metres in length or over. For a vessel of intermediate length the freeboard
should be determined by linear interpolation. The raised portion(s) of the
watertight weather deck should extend across the full breadth of the vessel and
the average freeboard over the length of the vessel should comply with 12.2.2.1
above for a vessel with a continuous watertight weather deck;
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.3 in the case of an open boat, have a clear height of side (i.e. the distance
between the waterline and the lowest point of the gunwalefootnote) of not less than 400mm for vessels of 7 metres in
length or under and not less than 800mm for vessels of 18 metres in length or
over. For a vessel of intermediate length the clear height should be determined by
linear interpolation;
12.2.4 Vessels which carry cargo or a combination of passengers, industrial personnel
and cargo for which the cargo element exceeds 1000kg.
12.2.4.1 Freeboard should be assigned in accordance with the Merchant Shipping (Load
Line) Regulations 1998 (SI 1998 No. 2241), as amended. See MSN 1752footnote, as amended, Schedule 5 Table B and calculation for ships
<24m and noting the corrections for Type B ships “other than timber freeboards” that
are required for lack of superstructure, lack of sheer, block coefficient, depth and bow
height shown in Schedule 4.
Such vessels should have a scale of draught marks marked clearly at the bow and stern.
12.2.5 A vessel required to be provided with an approved Stability Information Booklet
should be assigned a freeboard which corresponds to the draught of the vessel in sea
water when fully loaded (each person taken as 82.5kg), but which in no case should be
less than the freeboard required by section 12.2.3 or 12.2.4, nor that corresponding to
the scantling draught.
12.3 Freeboard Mark and Loading
12.3.1 A vessel assigned a freeboard in accordance with section 12.2.4 should be marked
with a freeboard mark in accordance with the Merchant Shipping (Load Line) Regulations
1998 (SI 1998 No. 2241), as amended, and have a scale of draught marks marked clearly at
the bow and stern, on both sides of the vessel. The longitudinal position of the draught
marks, relative to the longitudinal datum for the hydrostatic data, should be recorded
in the Stability Information Booklet, where provided.
12.3.2 Where it is considered that the addition of a scale of draught marks is neither
practicable nor meaningful, for example, due to restricted loading variations,
application for special consideration should be made to the Administration.
12.3.3 Additionally, where the line of the deck is not immediately discernible, a vessel
should be provided with a deck line. The deck line and freeboard mark should be
permanent and painted on a contrasting background.
12.3.4 The freeboard mark shall consist of a ring 300mm in outside diameter and 25mm
wide, intersected by a horizontal line 450mm long and 25mm wide the upper edge of which
passes through the centre of the ring. The top of the intersecting line should be
positioned at the waterline corresponding to the assigned freeboard to deck edge
amidships.
12.3.5 No mark should be applied for fresh water allowance.
12.3.6 The assigning letter marking on the bar of the ring and bar should be D on the
left and T on the right when the MCA is the Certifying Authority. In the case of any
other Certifying Authority, the assigning letters should be U on the left and K on the
right.
12.3.7 The freeboard mark for a vessel required to be provided with an approved
Stability Information Booklet, other than a vessel complying with section 12.2.4 and for
a vessel not required to be provided with an approved Stability Information Book, other
than inflatable boats and boats fitted with a buoyant collar, should be a bar of 300mm
in length and 25mm in depth.
12.3.8 The marking should be permanent and painted black on a light background or in
white or yellow on a dark background. No assigning letter marking should be placed on
the bar marking.
12.3.9 The top of the mark should be positioned at the waterline corresponding to the
draught referred to in section 12.2.5, at amidships.
12.3.10 Additionally, where the line of the deck is not immediately discernible, a
vessel should be provided with a deck line. The deck-line shall be marked amidships on
each side of the ship so as to indicate the position of the freeboard deck. The mark
need not be of contrasting colour to the surrounding hull.
12.3.11 Where the design of the vessel, or other circumstances, render it impracticable
to mark the deck line, the Certifying Authority may direct that it be marked by
reference to another fixed point as near as practicable to the position described above.
12.3.12 A vessel should not operate in a condition which will result in its freeboard
marks being totally submerged when it is at rest and upright in calm sea water.
12.4 Inflatable Boats and Boats Fitted with a Buoyant Collar
12.4.1 The freeboard of an inflatable boat or boat fitted with a buoyant collar should
be not less than 300mm measured from the upper surface of the buoyancy tubes and not
less than 250mm at the lowest part of the transom with all its equipment, fuel, cargo,
activity related equipment (e.g. diving equipment) and the number of persons for which
it is to be certificated on board, with the boat re-trimmed as necessary to represent a
normal operating condition, and with the drainage socks, if fitted tied up.
12.4.2 A freeboard mark is not required, except where the vessel is certified to carry
more than 1000kg of cargo in accordance with section 12.2.4 when a load line is
required. The minimum freeboards recorded during the tests of section 12.2.5.1 should be
recorded on the SWB2 and the permissible maximum weight which can be carried should be
recorded on the certificate for the vessel.
12.4.3 For boats operating in Area Category 6 only, which do not meet the freeboard
requirement of section 12.4.1 at the transom, may still be accepted by the Certifying
Authority provided it can be demonstrated that the boat is self-draining when moving
ahead, and has a substantial reserve of buoyancy (>10%). The Certifying Authority should
record such an acceptance in its report for the vessel (report form SWB2).