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Physical Environment
a place to discuss and follow the work

Knowledgeable WG members: briana sullivan (UNH), Jens Schröder-Fürstenberg (Germany), Tom Loeper (USA), Yves Le Franc (SHOM)

OLD ORIGINAL - Sample Test Data File:Physical Environment Test Data Sample.docx (NOTE: we are now using real samples from US Coast Pilot and US Sailing Directions)

NEW listing of terms with data source (Annex A)

File:Coast Chart Term Frequency NIPWG Version.xlsx - a new list of terms compiled from all possible sources related to the Physical Environment that contains statistics on the frequency of word use within the 9 volumes of the US Coast Pilot. It will be used as a guide to focus on terms to research and build use case scenarios so we know what is of value to model and what doesn't need representation.

Magnetic Variations and Local Anomalies

  • Magnetic Variations
  • Magnetic Anomalies


From DCEG Geo Feature Magnetic Data

Magnetic Variation - MAGVAR (4.1)

S-101 Geo Feature

The angle between the magnetic and geographic meridians at any place, expressed in degrees east or west to indicate the direction of magnetic north from true north. Also called magnetic declination. (IHO Dictionary –S-32).

(until a world magnetic model is universally available for inclusion in ECDIS mag var is most important magnetic data for the mariner. Updates should be supplied every five years to coincide with changes of epoch).

S-101 Attributes
  RYRMGV - reference year for magnetic variation. (YYYY)
  VALACM - value of annual change in magnetic variation. (+/- minutes: easterly/westerly)
  SCAMIN - scale minimum

Local Magnetic Anomaly - LOCMAG (4.2)

S-101 Geo Feature

An anomaly of the magnetic field of the Earth, extending over a relatively small area, due to local magnetic influences. Also called local attraction or magnetic anomaly. (IHO Dictionary –S-32).

If it is required to encode an abnormality in magnetic variation for a localised area, it must be done using the feature Local Magnetic Anomaly. If the area cannot be defined, the feature should be represented as a point.

S-101 Attributes
Feature Name
   display name
reported date SORDAT
value of local magnetic anomaly
    magnetic anomaly value maximum VALLMA
    magnetic anomaly value minimum 
scale minimum SCAMIN


Where the mandatory complex attribute value of local magnetic anomaly contains a value in the sub-attribute magnetic anomaly value maximum only, the deviation is assumed to be positive and negative by that amount. Where the positive and negative values for the local magnetic anomaly differ, the positive value must be populated in anomaly value maximum, and the negative value in the sub-attribute magnetic anomaly value minimum. The plus/minus character must not be encoded.

Abnormal magnetic variation should not be encoded unless it varies by more than about 3° from the normal magnetic variation (see clause 4.1) for the area.

Coast Pilot examples

(120) Differences of as much as 5° from the normal variation have been observed near the mouth of Smyrna River.   

(166) Differences of as much as 2° to 5° from normal variation have been observed along the channel from Artificial Island to Marcus Hook. 

(232) Differences of 2° to 5° from normal variation have been observed astride the Delaware River Channel from Oldmans Point to the mouth of Oldmans Creek.  

(79) Differences of as much as 6° from the normal variation have been observed in Elk River Channel from Courthouse Point to Old Town Point. 

(30) Differences of as much as 6° from the normal variation have been observed 3 to 17 miles offshore from Cape Henry to Currituck Beach Light. 

(130) Differences of as much as 5° from the normal variation have been observed in the channel from Pooles Island to Howell Point (chart 12274). 

(180) Differences of 3° to 8° from normal variation have been observed in Elk River channel from Grove Point to Courthouse Point. 

Possible Data Elements Needed

Observation location description - would it be HELPFUL to have the cultural points within the area maintained?

(perhaps it is more understandable for someone to keep in their mind map of the area the familiar names delineating the locations vs only an outline on the chart?)


For the US... the Magnetic Variation area is the bounds of a given chart...yet the Coast Pilot clearly has variations that are within the magnetic variation bounds of the chart. (Yet there are none encoded in the ENC).

Ice Conditions

  • Drift Ice
  • Icebergs



Ice Area ICEARE (5.13)

S-101 Geo Feature (Surface)

An area of ice over land or water. (S-57 Edition 3.1, Appendix A –Chapter 1, Page 1.84, November 2000).

S-101 Attributes
category of ice (CATICE)
    1 : fast ice
    5 : glacier
    8 : polar ice
elevation (ELEVAT)
feature name  
    display name
height  (HEIGHT)
periodic date range
    date end(PEREND)
    date start(PERSTA)
reported date(SORDAT)
    1 : permanent
    5 : periodic/intermittent
    18 : existence doubtful
vertical length(VERLEN)
visually conspicuous  (CONVIS)        
    1 : visually conspicuous
    2 : not visually conspicuous
    3 : prominent
scale minimum (SCAMIN)


Ice Area features that are located in the sea must be covered by an Unsurveyed Area feature, if the depth of water beneath them is unknown, or covered by a Depth Area feature, if the depth is known.

As ice fronts move, a date when the limit was surveyed should be included, if possible, using the attribute reported date.

Glaciers(see S-4 –B-353.8) If it is required to encode the portion of a glacier that is on land, it must be done using an Ice Area feature, with attribute category of ice= 5 (glacier) covered by a Land Area feature (that is, the glacier does not form a hole in the land area).

If the seaward edge of an encoded glacier is coincident with the coastline, this edge should be encoded using a Coastline feature, with attribute category of coastline=6 (glacier (seaward end)), and the coastline’s spatial type should have the attribute quality of horizontal measurement=4 (approximate) for the visible coastline.

Coast Pilot examples

(97) The intracoastal passages of New Jersey, Delaware and Maryland usually are closed by ice during ordinary winters; the Virginia passages are closed only during severe winters and then only for short periods. Local vessels use all the inlets and adjacent channels from Sandy Hook to Cape Charles all winter, even when through navigation is blocked.

(98) In Delaware River, ice is present in sufficient amounts even in ordinary winters to be of some concern. The Chesapeake and Delaware Canal is kept open as long as possible but may be closed at times. In severe winters, navigation has been interrupted above Chester but tugs and large vessels keep the channels open to Philadelphia. Above Philadelphia, the river may be closed for extended periods in January and February, and navigation is practically suspended during severe winters.

(99) Ice seldom interferes with navigation of full-powered vessels in Hampton Roads even in severe winters. Large vessels can always pass up and down Chesapeake Bay, but ice jams are of frequent occurrence off Baltimore Harbor. The harbor itself sometimes freezes over and navigation may be blocked for small, low-powered vessels for limited periods.

(100) Conditions in other Chesapeake Bay tributaries are somewhat similar to those in the same latitudes along the coast. Ice is not much of a problem in the southerly tributaries. The upper part of Potomac River is closed during severe winters, and Patuxent River is closed nearly to the mouth. Severn River, strangely enough, is said to remain open except for short periods in severe winters. Susquehanna River, at the head of the bay, usually is completely closed for about 3 months. Ice conditions in the Eastern Shore tributaries correspond roughly to those across the bay.

(101) During some winter months or when threatened by icing conditions, lighted buoys may be removed from station or replaced by unlighted buoys; unlighted buoys, daybeacons and lights on marine sites also may be removed. (See LIGHT LIST.)

(102) For icing hazards to vessels see Superstructure icing, following.

(135) Ice may be encountered on Maurice River from the latter part of December through the early part of March.

(87) Ice sufficient to interfere with the navigation of small craft may be expected at any time between December and April and is worst during January and February. The canal is kept open as long as possible. During mild winters, local vessels use the canal throughout most of the season, but strangers should make inquiries before attempting passage. Wooden vessels passing through thin ice are liable to be cut through at the waterline. Vessels with low horsepower are cautioned against transiting the canal in heavy ice. 

Possible Data Elements Needed

type of ice - ice barriers, impoundments, pack ice (Germany), thin ice, heavy/heavier ice, sufficient ice (US)

disability - ice pressure, passage disability (Germany), interruption

closure times - ordinary winters, severe winters (US)

closure duration - short periods, extended periods, entire winter (data range) (US)

seasonal notes on passage/navigation - ice seldom forms before January

applicability - local vessels, strangers, small, low-powered/low horsepower vessels, large vessels, full-powered vessels, Wooden vessels


would S-101 feature name contain the ice area names included in the text (ex: New Jersey, Delaware, Maryland intracoastal passages, Virginia passages, channels from Sandy Hook to Cape Charles). If not, it might be a data element for S-126 Ice Area Name(s).

S-101 ICEARE - CATICE - is fast ice also "running ice" or "moving ice"? S-101 ICEARE - periodic date range - textual descriptions have ranges with types of ice (ex. Thin ice has been known to form early in December between Chester and Philadelphia, but the heavier ice usually does not begin to run before January.)

Currents and Flow

    • General Information
    • Named Currents
    • Seasonal Currents

Current –non-gravitational



Water turbulence (WATTUR) The disturbance of water caused by the interaction of any combination of waves, currents, tidal streams, wind, shoal patches and obstructions. (IHO Dictionary –S-32

category of water turbulence  (CATWAT)
    1 : breakers
    2 : eddies
    3 : overfalls
    4 : tide rips
    5 : bombora
feature name
    display name
    name(OBJNAM) (NOBJNM)
scale minimum (SCAMIN)

S-101 Geo Feature:Current –Non-Gravitational (CURENT) 10.3

IHO Definition: CURRENT –NON-GRAVITATIONAL. Any current that is caused by other than tide producing forces. Also called non-tidal current.(IHO Dictionary –S-32).

S-101 Attributes
feature name  
   display name
   name(OBJNAM) (NOBJNM)
fixed date range
   date end (DATEND)
   date start (DATSTA)
   orientation uncertainty
   orientation value (ORIENT)
periodic date range
   date end (PEREND)
   date start (PERSTA)
   speed maximum (CURVEL)
   speed minimum

Status (STATUS) scale minimum (SCAMIN)


10.3.1 Current data (see S-4 –B-408)The term “current(s)” in this document is used to describe water movements which are generally constant in direction, and are not dependent on astronomical conditions (that is, are non-gravitational). A current is described by the direction towards which it is running. For tidal streams, see clauses10.2 and 10.5.

Currents occur as:

The flow of river water in rivers and estuaries;

Permanent flows in other restricted waters, for example İstanbul Boğazı (Bosporus);

Permanent or seasonal oceanic currents; Temporary wind-induced currents.

Only surface currents should be encoded. It is particularly important to depict currents (both the main flows and permanent eddies) which could set a vessel towards dangers.

Coast Pilot examples

(95) Rotary currents and Gulf Stream currents could be discussed at considerable length, but the important currents are those in the inlets and the inside passages; the tidal currents have considerable velocity in all of the entrances, and their direction is affected by the force and direction of the wind. (See the Tidal Current Tables at tidesandcurrents.noaa.gov/curr_pred.html for detailed information.)    --- 

(96) The current velocity is about 2 knots in Cape May Inlet. 


(19) Current velocities may reach 3 knots in the inlets and in the narrow channels that connect the inlets with the inside waters. 


(40) The current velocity in Manasquan Inlet is about 1.8 knots in the inlet and 2.2 knots at the State Route 35 bridge.  --- 

(91) Cross currents may be experienced in the approach channel to Tuckerton Creek. A speed limit of 8 miles per hour is prescribed for the channel. (See 33 CFR 162.30, Chapter 2.) 


(176) In Cape May Canal, the current velocity is 1.9 knots at the east end and 0.9 knot at the west end; passage of barge tows may be delayed because of tide and current conditions.   --- 

(51) The current velocity is 1.8 knots in Delaware Bay entrance. (See the Tidal Current Tables for daily predictions.) The tables also list current differences and other constants for about 55 other places in Delaware Bay and River 


(99) The current velocity is 1.5 knots on the flood and 1.0 knot on the ebb. In 1980, it was reported that current velocities up to 3 knots on the flood and 4 knots on the ebb may be encountered in the river. Occasional periods of lower than normal low water levels were encountered. 


(111) The current velocity off the entrance is about 0.7 knot. 


(123) The channels have strong currents, and many tide rips form near Prissy Wicks Shoal. In unmarked Cape May Channel, the current velocity is 1.5 knots on the flood and 2.3 knots on the ebb. In the channel immediately northwestward of Overfalls Shoal, the velocity is 2 knots on the flood and 1.9 knots on the ebb. 


(133) The current velocity is about 1 knot in the entrance and about 2.3 knots at Mauricetown; at Millville, the flood is very weak and the ebb velocity is 0.4 knot. Owing to dereliction of the dikes along the river, greater current velocities have been reported; extreme care is required in docking 


(154) High water at Bridgeton is about 2 hours later than at the entrance. The current velocity is about 1.3 knots half a mile above the entrance and less than 0.5 knot at Bridgeton. 


(171) The tides at Salem are about 35 minutes later than at Reedy Island. The current velocity is about 1.6 knots in the entrance. The maximum expected current in the land cut is 3 knots 


(237) The current velocity is about 1.7 knots at Marcus Hook. 


(256) The current velocity is 1.7 knots on the flood and 2.2 knots on the ebb off Eddystone, Mile 73N. 


(264) The current velocity is about 2 knots a half-mile east of Crab Point. 


(272) The current velocity is about 2 knots in the channel opposite the anchorage. 


(344) In Schuylkill River, the current velocity is about 0.5 knot at the entrance. 


(398) The current velocity is 1.3 knots on the flood and 1.6 knots on the ebb in the main channel west of Burlington Island. In the back channel east of the island, the velocity is 0.9 knot on the flood and 1.8 knots on the ebb. 


(408) The current velocity in Whitehill Range off Fieldsboro is 1.4 knots on the ebb; the flood current is weak and of short duration. 


(85) The current velocity is 2.6 knots on the flood and 2.1 knots on the ebb at the Reedy Point bridge and about 2 knots at the Chesapeake City bridge. The flood sets eastward and the ebb westward. (See the Tidal Current Tables for daily predictions for Chesapeake City.) Storms may increase these velocities to 3.0 knots or more; at such times, tows usually have difficulty in making headway against the current. 


(20) The currents have considerable velocity in the inlets and in the narrow channels connecting the inlets with adjacent bays and sounds. Velocities of as much as 3 knots may be encountered at times in places where the currents are strongest. 


(45) The current velocity is about 2 knots; caution is necessary, because the buoys sometimes tow under. 


(51) The current velocity is 1.0 knot on the flood and 1.5 knots on the ebb in Chesapeake Bay Entrance. (See the Tidal Current Tables for daily predictions.) 


(15) The currents in James River follow the general direction of the channel, except between Hog Island and Jamestown Island, 25 miles above the mouth, where they set across Goose Hill Flats. In the lower reaches, the velocity of flood is about equal to that of ebb. Near Richmond, the drainage flow predominates and the current seldom, if ever, sets upstream. These normal conditions are subject to change by wind and freshets.  

(16) During severe winters some drift ice appears, and at times the river freezes over, but navigation to Richmond hardly ever is suspended because the ice is broken up by a tug.  

(17) Freshets occur irregularly in the fall, winter and spring; their height at Richmond ranges from 6 to 32 feet, though the latter is exceptional. The maximum freshet heights usually occur between the middle of March and the middle of April; the freshets occurring at other times usually reach heights not greater than about 6 feet above the normal high water. The number of freshets that cause the water to rise above the level of the wharves along the main channel at Richmond averages about one per year; the water seldom rises above the level of the city wharf. The flood heights diminish rapidly below Richmond; the extreme is about 11 feet less at Dutch Gap, and the rise is not felt at Hopewell. The cutoffs have reduced the freshet height at Richmond about 1 foot. 


(30) In Nansemond River, the current velocity is about 0.9 knot and follows the general direction of the channel 


(135) The currents follow the general direction of the channel. The velocities throughout the river are usually weak, averaging less than 1 knot at the entrance to 1.4 knots at Tappahannock. Times of slack water and strength of current become later going upriver. These normal conditions are subject to change by winds and changes in drainage flow 


(22) The current in Chesapeake Bay off the mouth of Potomac River can be hazardous to smaller vessels and pleasure boats at ebb tide, when wind and current are opposed and with northwest winds. These conditions are more pronounced off Smith Point. The currents in the Potomac River follow the general direction of the channel. The velocities vary throughout the river and are influenced by wind and freshets. There may be little or no flood current during freshets. (23) The current velocity is weak in the lower part of the river between the entrance and Piney Point, averaging less than 1.0 knot. (See Tidal Current Tables for predictions.) 


(106) Strong tidal currents set across the main channel off Monie Bay; the current velocity in the entrance to the river is 0.6 knot on the flood and 0.9 knot on the ebb.  ---  (130) The current velocity in Nanticoke River is 1.2 knots in the entrance. The water is fresh above Vienna. Ice forms on the river in winter, but ordinarily there is enough traffic to keep the channel open. Spring freshets do not interfere with navigation. 


(277) The current velocity is less than 1.0 knot. The river is usually closed to navigation by ice for extended periods during ordinary winters; in mild winters the channel is kept clear most of the time by powerboats. The river water is fresh above Chestertown. 


(39) Prolonged winds of constant direction may cause substantial variation in the tide. Currents in the harbor are 0.8 knot on the flood and ebb. 

Germany Example

at S to W winds expiring flow

at N to O winds incoming flow

Flow rates up to 2.5 nm/h

   Maximum in the Friedrichsorter Enge

the lighthouse Kiel at strong NO and SO-W-winds Liche flow to 2 sm/h

Possible Data Elements Needed

    velocity value- float 
    Velocity units - knot
    Velocity qualifier - (equal to), less than, greater than, about
    Velocity direction - flood, ebb, flood and ebb, none
Feature - some ENC feature names, some locations described, a waterMovement Area (polygon)
Relation To Feature - above, in, near, at, off, east of, throughout
Tidal Current strength - strong
Tidal Current Direction of set - follow the general direction of the channel, The flood sets eastward and the ebb westward
Warning Note
Water Level


Tidal Streams - flood/ebb


From DCEG Geo Feature: TidalStream –Flood/Ebb (TS_FEB)

IHO Definition: TIDAL STREAMS. The alternating horizontal movement of water associated with the rise and fall of the tide caused by tide-producing forces. Also called tidal current. (IHO Dictionary –S-32). Approximate tidal stream rates may be given as discrete rate values for flood and ebb flow during springs. (S-57 Edition 3.1, Appendix A –Chapter 1, Page 1.173, November 2000).

S-101 Attributes

Coast Pilot examples

Possible Data Elements Needed


Sea Level and Tides

  • Sea Level
  • Tides

Sea and Swell

  • Sea Conditions
  • Swell Conditions
  • Tropical Disturbances
  • Abnormal Waves

Sea Water Characteristics

  • Salinity
  • Density
  • Sea Surface Temperature

Maritime Topography

(these terms origniated from scanning the publications and discussing among the group which were the most SIGNIFICANT features a mariner needed for navigation)

  • General Remarks
    • Chart reference
    • general description of the area (topological as well as submarine)
  • Seabed and Features
    • Deeps
    • Ridges and Plateaux
    • Shoals and Banks
  • Submarine Springs
  • Volcanic Activity
  • Seismic Activity

Climate and Weather

  • General Information
  • General Conditions
    • Climate
    • Visibility
    • Cyclones
  • Pressure
    • Average Distribution
    • Variability
    • Diurnal Variation
    • Abnormal Falls
  • Anticyclones
    • Sub-tropical high pressure belt
  • Depressions
    • General Information
    • Cyclones, tropical storms, tropical depressions
    • Classification
    • Occurrence
    • Average occurrence of tropical storms and cyclones in the SW indian ocean (this seems too specific for a heading)
    • Movement
  • Fronts
    • Cold Fronts
    • The intertropical convergence zone
  • Winds
    • General information
    • South-east trade winds
    • The North-west monsoon
    • Light or moderate variable winds
    • The Westerlies
    • Coastal Areas
    • Land and sea breeze
  • Gales
    • General Information
    • Winds north of 30°S
    • Winds south of 30°S
    • Squalls
    • Waterspouts
  • Cloud
    • North of 30°S
    • The sub-tropical belt of high pressure
    • South of 30°S
  • Precipitation
    • General Information
    • The North-west monsoon and ITCZ
    • Madagascar
    • La Reunion, tec
    • Cycolones
    • The sub-tropical belt of high pressure
  • Fog and visibility
    • Sea fog
    • Radiation fog
  • Air Temperature
    • Open sea
    • Coastal areas
  • Humidity
    • General Information
    • Open sea N of 30°S
    • South of 30°S

Climate Information

  • Climate Station Information


  • Where are the Physical Descriptions of features, approaches, ports, anchorages, etc?
  • Are references to external documents (i.e. Mariner's Handbook) to be kept or actual data from the reference or attach pdf?
  • S-26 ?(undersea feature names) should be incorporated into this