If you cross a shipping channel in a small boat, run an inlet after dark, or share an intracoastal reach with tugs and ferries, you want to know what else is moving before you commit. Helm puts live AIS vessel traffic on the same chart you are navigating with, on iPhone and iPad, so the ship you are about to cross in front of is a target on the screen with a position you can measure against your own.
AIS stands for Automatic Identification System. Turn the layer on and live traffic draws over the chart you are already using, in the same coordinates as your own boat. The geometry between you and a ship becomes something you read off the screen instead of something you estimate from a low helm seat.
Each target carries a vessel type, taken from the standard ITU-R M.1371 type codes, and a movement status. An anchored tanker reads differently from one under way, so a line of ships holding off a port approach is immediately a different thing from a ship making for the channel. The visible area refreshes about every ten seconds while the layer is on, so targets move on your screen as the traffic moves on the water.
| Field | What you do with it on the water |
|---|---|
| Position | Puts the vessel on your chart in the same coordinates as your own boat, so the geometry is visible instead of guessed. |
| Vessel type | Tells a working tug apart from a ferry on a schedule, and a fishing vessel apart from a container ship, before the shape resolves. |
| Movement status | Separates the traffic that is going somewhere from the traffic that is sitting still, which is most of the decision in a crowded approach. |
| Refresh | The visible area updates about every ten seconds, so a target is where the screen says it is. |
You are running a center console across a marked channel in a port approach. From low down, a ship head-on and a ship at an angle look almost identical, and a loaded ship covers the width of a channel far faster than it looks from a helm seat. On the chart in Helm that ship is a target with a position that updates while you watch it, so you can see it eat the distance and decide to cross ahead or hold and pass astern.
A tug pushing a barge is a long object with a dark gap in the middle, and the gap is the part that hurts. Helm gives you the tug as a target with a vessel type on it well before the lights resolve into something you can name, and the night chart style keeps the screen readable while your eyes stay adjusted to the dark.
Fog turns a busy inlet into guesswork for the eye. On the chart you still have the ferry moving in on your port bow and the fishing vessel working the edge of the channel, both placed on the same water you are steering through, so you slow at the right moment and hold where it makes sense.
Inlet traffic at the end of a weekend is a stream of boats funneling through one narrow line at different speeds. Seeing the commercial traffic in that stream, which of it is under way and what is sitting at anchor off to the side, tells you which part of the channel to be in before you are inside it.
Helm keeps what you need while underway on one strip: depth under the keel, speed over ground and course over ground. Vessel traffic sits on the same chart, above the same shaded water Helm works out from your boat's draft. That matters when the obvious way to give a ship room is to slide out of the channel. Enter your draft once and Helm shades the water you cannot cross and plans routes around it, so the room you take is room you actually have.
The depth under that traffic comes from four sources: NOAA electronic navigational charts, USACE eHydro dredging surveys, state lake elevation data and live tide from NOAA CO-OPS, with CATZOC, the chart's own confidence rating, surfaced on the chart. The rest of the underway picture is on the same screen: an anchor alarm that wakes you if you drag once you stop for the night, satellite and night chart styles, and a logbook that records every trip so you can replay how you handled a passage later.
The night palette drops the chart to deep, low-output colors so your eyes stay adjusted to the dark. Vessel targets, your own track and the depth strip stay legible on the same screen you were using in daylight.
Helm. It shows live vessel traffic on the same NOAA chart you are navigating with, on iPhone and iPad, alongside depth from four sources, tides, currents and weather.
The visible area refreshes about every ten seconds while the AIS layer is on, so targets keep pace with the traffic while you watch a crossing develop.
Yes. Each target carries a vessel type from the standard ITU-R M.1371 type codes and a movement status, so a tanker at anchor reads differently from one under way, and a tug reads differently from a ferry on a schedule.
Yes. Traffic sits on the chart you are already using, over the depth shading Helm works out from your draft and next to the depth, speed and course strip. Routes you plan, spots you mark and the logbook carry across your iPhone and iPad.
Yes. Switch to the night chart style and traffic, your track and the depth, speed and course strip all stay readable in deep low-light colors.
Yes. Helm is native on iPhone and iPad, so the traffic picture is on the bigger screen at the nav station as well as the phone at the helm.
Helm Boating