Reference
Glossary
23 terms that make a vessel page readable, from upbound and downbound to Boatnerd.
The vocabulary the rest of the site uses without stopping to explain it. Where a word carries a particular meaning in the passage record, chokepoint and passage and range among them, this is the meaning the data uses.
- Upbound and downbound
- Upbound is toward Lake Superior, the head of the system; downbound is toward the St. Lawrence and the sea. It has little to do with north and south, and a boat leaving Duluth for Cleveland is downbound the whole way. At harbor entries this site says inbound and outbound instead, and at the Straits of Mackinac, westbound and eastbound.
- Passage
- One vessel track crossing one of our gate lines, timed at the AIS sample nearest the crossing. It is not a lockage, a bridge transit, a voyage or a cargo: a single round trip from Duluth to Detroit produces several passages, and two crossings by the same boat within three hours are counted once, because a boat waiting her turn drifts back and forth over the line. Every count on this site is a count of passages in that sense.
- Range, or habitat
- Where a hull has actually been seen, rather than where a registry says she may go. The export calls the field habitat and the pages label it range. It is inferred from the AIS tracks we hold and takes three values: lakes only, for a boat observed nowhere but inside the lakes; lakes and Seaway, for one that also works down the Seaway; and Seaway visitor, for an ocean-going salty in on a voyage. It is a reading of observed tracks and not a registry fact, so a boat can change category by making one trip we had not previously seen.
- Laker
- A vessel built for this system and normally confined to it: long, shallow, flat-sided, built to fill a lock chamber. Lakers do not cross oceans, and the largest of them cannot leave the upper four lakes.
- Salty
- An ocean-going ship visiting the lakes through the St. Lawrence Seaway. Salties are smaller than the big lakers because they have to fit the Seaway locks, and many of the hulls in our archive with no lakes fleet attached are salties passing through on a single voyage.
- A laker of roughly 1,000 by 105 feet, the largest class on fresh water. Thirteen were built and all are US-flagged. Twelve of them appear in our archive, and not one has ever crossed our Welland chokepoint: the Seaway locks are 766 feet long, so a footer's world ends at Lake Erie.
- Seawaymax
- The largest hull that fits the Seaway and Welland locks, about 740 by 78 feet. Canadian fleets build right up to it, which is why so many Algoma and CSL boats in our data report 225 by 24 meters over AIS.
- Self-unloader
- A boat that discharges her own cargo with a conveyor under the hold and a boom that swings out over the dock. Most of the US fleet self-unloads, which is why a laker can work at a berth with nothing on it.
- Straight-decker
- A bulk carrier with no unloading gear of her own, dependent on shoreside cranes or rigs. Grain boats are often straight-deckers; our roster calls them gearless bulkers.
- ATB
- An articulated tug and barge: a tug locked into a notch in the stern of a barge so the pair works as one unit. An ATB counts as one passage here and usually appears under the tug's AIS name, which is why names like Joyce L. Vanenkevort turn up in a list of freighters.
- Soo Locks
- The locks at Sault Ste. Marie, Michigan, which lift boats about 21 feet between Lake Huron and Lake Superior. Two are in service: the MacArthur, 800 by 80 feet, and the Poe, 1,200 by 110 feet, the only chamber a thousand-footer fits. Nothing is published in advance; lockages happen as boats arrive.
- Welland Canal
- Eight locks over about 27 miles carrying boats around Niagara Falls, a lift of about 326 feet between Lake Ontario and Lake Erie. Locks 4, 5 and 6 at Thorold are twinned flight locks, and our Welland gate line is drawn across the canal there.
- Order of turn
- The queue for a lock. The Seaway publishes an order-of-turn table for its own locks, which is as close to a schedule as this system offers.
- Seaway location codes
- The short codes in the Seaway's transit board — CVC, MLO-S, L4W — naming where a ship last reported and where she is expected next. The Seaway publishes no legend for them, so we built one: a lock code names the chamber and, where a letter follows, the wall she is tied to, and in the Welland Canal a lock's north wall is its lower end. C-numbers are the Seaway's numbered call-in points and B-numbers are Welland Canal bridges. The open-lake checkpoints — Cape Vincent, Sodus Point, Mid-Lake Ontario, Newcastle, Long Point — carry the crossing track, north, centre or south. Our readings come from the Seaway's own per-vessel detail pages, its ship-transit handbook and the calling-in table in the Seaway regulations; the handful of codes none of those three confirm are printed bare rather than guessed at.
- Lay-up and fit-out
- Lay-up is a boat tied up and shut down, either for the winter or for years at a time; fit-out is the spring work of waking her, crewing up and running trials before the first trip. Fit-out dates are March news in the lake ports.
- Winter work
- The maintenance squeezed into lay-up: hull, engines, cargo gear, inspections. Some boats go to a yard at Sturgeon Bay or Toledo and some are worked where they sit.
- Gales of November
- Late-autumn storms, made by cold air arriving over water still warm from summer. They sank the Edmund Fitzgerald on 10 November 1975 and took a far heavier toll in the storm of November 1913. Traffic keeps running through them, which is part of why November watching is good.
- Master salute
- One long blast and two short, answered in kind, exchanged between vessels and with shore. At Duluth the Aerial Lift Bridge answers it, and that exchange is what most of the crowd came for.
- Rock Cut
- The blasted channel on the west side of Neebish Island below the Soo, used by downbound traffic while upbound boats take the East Neebish channel. It is narrow enough that a big laker looks like she is being driven down a ditch.
- Taconite
- Iron ore concentrated into pellets, the cargo behind most of the traffic at the head of the lakes. It loads at Duluth, Superior, Two Harbors, Silver Bay and Marquette for steel mills on the lower lakes.
- AIS and MMSI
- AIS is the VHF position-reporting system commercial vessels broadcast; the MMSI is the nine-digit identifier in every message, and it is the key this whole site is built on. Names and dimensions in AIS are entered by crews, so spellings wander and a few numbers are plainly wrong.
- Chokepoint
- Our word for a place every boat has to pass, and on this site also a line drawn across that channel. A passage is a track crossing the line, which is not quite the same event as a lockage or a bridge transit.
- Boatnerd
- What the community calls itself, after boatnerd.com, which has carried the hobby since the 1990s and still runs the live map and the community passage lists.