Version 2025.0.01

18.0 Seabed Sample Encoding

For Field Units who have submitted a feature file containing seabed samples to the Office of Coast Survey, the following S-57 attribution must be used per the legend below.

 

(m) Mandatory
(c) Conditional
(r) Restricted

18.1 Sediment Size Classification

  1. Type
  1. Term
  1. Grain Size (mm)
  1. Clay
  1.  
  1. < 0.002
  1. Silt
  1. 0.002 - 0.0625
  1. Sand
  1. fine
  1. 0.0625 - 0.25
  1. medium
  1. 0.25 - 0.5
  1. coarse
  1. 0.5 - 2.0
  1. Gravel
  1.  
  1. 2.0 - 4.0
  1. Pebbles
  1. 4.0 - 64.0
  1. Cobble
  1. 64.0 - 256.0
  1. Boulder
  1. > 256.0
  1. Stone
  1. 4.0 - 256.0+

 

18.2 NATSUR/NATQUA Attribution

Attribute Description
NATSUR (m) Nature of Surface (m)
  '1' mud (m) Soft, wet earth.
'2' clay (m) Particles less than 0.002mm; stiff sticky earth that becomes hard when baked.
'3' silt (m) Particles of 0.002 - 0.0625mm; when dried on hand will rub off easily.
'4' sand (m) Particles of 0.0625 - 2.0mm; tiny grains of crushed or worn rock.
'5' stone (m) A general term for rock fragments ranging in size from pebbles and gravel to boulders or a large rock mass.
'6' gravel (m) Particles of 2.0 - 4.0mm; small stones with coarse sand.
'7' pebbles (m) Particles of 4.0 - 64.0mm; small stones made smooth and round by being rolled in water.
'8' cobbles (m) Particles of 64.0 - 256.0mm; stones worn round and smooth by water and used for paving.
'9' rock (m) Any formation of natural origin that constitutes an integral part of the lithosphere. The natural occurring material that forms firm, hard, and solid masses.
'11' lava (m) The fluid or semi-fluid matter flowing from a volcano. The substance that results from the cooling of the molten rock.
'14' coral (m) Hard calcareous skeletons of many tribes of marine polyps.
'17' shells (m) Exoskeletons of various water dwelling animals.
'18' boulder (m) A rounded rock with diameter of 256mm (25.6cm) or larger.
  • List in order of most predominant first, comma delimited.
NATQUA (c) Nature of Surface - qualifying terms (c)
  '1' fine (c) Falls within the smallest size continuum for a particular NATSUR term.
'2' medium (c) Falls within the moderate size continuum for a particular NATSUR term.
'3' coarse (c) Falls within the largest size continuum for a particular NATSUR term.
'4' broken (c) Fractured or in pieces.
'5' sticky (c) Having an adhesive or glue like property.
'6' soft (c) Not hard or firm.
'7' stiff (c) Not pliant; thick, resistant to flow.
'8' volcanic (c) Composed of or containing material ejected from a volcano.
'9' calcareous (c) Composed of or containing calcium or calcium carbonate.
'10' hard (c) Firm; usually refers to an area of the seafloor not covered by unconsolidated sediment.
  • Must accompany NATSUR. Cannot occur alone.
  • Listed in the same order as the NATSUR attributes which they are associated with, and must be comma delimited. For any NATSUR that has no NATQUA qualifier, its place in the list must be left empty and held by a comma.
COLOUR (c) Color (c)
  '1' white (c)  
'2' black (c)  
'3' red (c)  
'4' green (c)  
'5' blue (c)  
'6' yellow (c)  
'7' grey (c)  
'8' brown (c)  
'9' amber (c)  
'10' violet (c)  
'11' orange (c)  
'12' magenta (c)  
'13' pink (c)  

 

18.3 NATSUR/NATQUA Allowable Attribute Combinations

  1. NATSUR
  1. NATQUA
  1. '1' fine
  1. '2' medium
  1. '3' coarse
  1. '4' broken
  1. '5' sticky
  1. '6' soft
  1. '7' stiff
  1. '8' volcanic
  1. '9' calcareous
  1. '10' hard
  1. '1' mud
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1. o
  1. o
  1. o
  1. o
  1. '2' clay
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1. o
  1.  
  1.  
  1. o
  1. '3' silt
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1. o
  1.  
  1.  
  1. o
  1. '4' sand
  1. o
  1. o
  1. o
  1.  
  1.  
  1. o
  1.  
  1. o
  1. o
  1. o
  1. '5' stone
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1.  
  1. '6' gravel
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1.  
  1. '7' pebbles
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1.  
  1. '8' cobbles
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1.  
  1. '9' rock
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1.  
  1. '11' lava
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. o
  1.  
  1.  
  1. '14' coral
  1.  
  1.  
  1.  
  1. o
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. '17' shells
  1.  
  1.  
  1.  
  1. o
  1.  
  1.  
  1.  
  1.  
  1. o
  1.  
  1. '18' boulder
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1.  
  1. o
  1. o
  1.