3.1 Bridge-to-Bridge Operations & VTS

3.1 Bridge-to-Bridge Operations & VTS

Quick Answer: A bridge-to-bridge station is VHF gear on the ship’s navigational bridge (or main control station) used only for navigational communications. In most U.S. waters the bridge-to-bridge watch is Channel 13 at 1 watt normal power. The Coast Guard’s Vessel Traffic Service (VTS) manages designated waterways to prevent collisions, groundings, and environmental harm. Keep navigation traffic short on Ch-13; keep the distress/safety/calling watch on Channel 16 (unless a specific VTS/GMDSS watch arrangement applies).

Element 1 Subelement B tests how commercial operators handle navigational voice procedures as well as distress and routine calling. Bridge-to-bridge work sits at the center of everyday ship safety: two bridges talking so vessels meet, overtake, and transit locks or bridges without a collision.

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What Is a Bridge-to-Bridge Station?

Under Part 80 definitions, a bridge-to-bridge station is:

• Located on the navigational bridge or main control station of the ship
• Operating in the 156–162 MHz VHF maritime band
• Used only for navigational communications

It is not an internal ship phone link between the wheelhouse and the radio room. It is not a portable “spare” station license for hopping vessels. It is not a general ship-to-shore business radio. If the message is about company cargo, crew payroll, or personal phone calls, it does not belong on bridge-to-bridge channels.

Primary purpose

The primary purpose of bridge-to-bridge communications is navigational communications—for example:

• Meeting and overtaking arrangements (“one whistle,” port-to-port, etc.)
• Intentions in narrow channels, bends, and restricted visibility
• Communications with lock masters and drawbridge tenders
• Short navigational coordination with nearby vessels

Messages must stay short. Congested waterways depend on everyone hearing the next meeting arrangement, not long chit-chat.

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Channel 13: The Bridge-to-Bridge Watch

Exam anchor: “Which channel is utilized for the required bridge-to-bridge watch?” → VHF-FM on Ch-13 in most areas of the continental United States—not Ch-16, not Ch-70 DSC, and not “whatever working channel the vessel prefers.”

Power rules you will be tested on

Normal bridge-to-bridge power is 1 watt. Higher power on Channel 13 is legal when:

1. Broadcasting a distress message, and/or
2. Rounding a bend in a river or traveling in a blind spot, and/or
3. During an emergency, and/or
4. Failure of the vessel being called to respond

Pool wording combines several of these ideas:

• “When may a bridge-to-bridge transmission be more than 1 watt?” → When broadcasting a distress message and rounding a bend / blind spot
• “When is it legal to transmit high power on Channel 13?” → All of these (failure to respond, blind situation, emergency)

Operator habit: default the radio to low power (1 W) on Ch-13. Raise power only when safety requires it, then return to 1 W.

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Vessel Traffic Service (VTS)

Vessel Traffic Service (VTS) is the U.S. Coast Guard traffic-management service in certain designated water areas. Its purpose is to prevent:

• Ship collisions
• Groundings
• Environmental harm (oil spills, hazardous cargo incidents, channel blockages)

VTS areas use designated VHF working channels (often port-operations or VTS-specific channels such as Ch-14 in some ports). Operators in a VTS area must:

• Monitor the assigned VTS channel(s) as required
• Follow Coast Guard / VTS traffic instructions
• Keep transmissions professional, short, and navigationally relevant

How VTS relates to Channel 16 watches

Element 1 also tests watchkeeping interplay:

• Outside special arrangements, compulsory vessels maintain a continuous radiotelephone watch on Channel 16 (and often 2182 kHz for MF-fitted non-GMDSS ships outside harbor).
• When a vessel is in a VTS system, is subject to the Bridge-to-Bridge Act, and is operating under the applicable A1/VTS rules, a Ch-16 watch may not be required if the vessel monitors both Channel 13 and the VTS channel—the pool’s “all of the above” style item treats several Ch-16 watch statements as true together.

Practical takeaway for GROL candidates: do not treat Ch-13 and Ch-16 as interchangeable. Ch-13 = navigation / bridge-to-bridge. Ch-16 = distress, safety, and calling. VTS adds a third layer of local traffic control. Many bridges run dual watch or multiple receivers so navigation and distress watches are continuous.

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Identification on Bridge-to-Bridge Channels

A ship station using VHF bridge-to-bridge Channel 13 may be identified by the name of the ship in lieu of call sign. That does not mean identification is optional. It means the familiar voice format—“Motor Vessel Example, one whistle, meeting you green-to-green”—is legally acceptable on the navigational channel. On other maritime channels, normal call-sign identification rules still apply (beginning and end of transmissions, and at required intervals).

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Operator Discipline on Navigational Channels

Bridge-to-bridge radio is collision-avoidance infrastructure. Treat it like a short-range safety circuit shared by every ship in the fairway—not like a private bridge telephone.

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Exam Memory Map

1. Definition → VHF on bridge/main control, navigational only
2. Purpose → Navigational communications
3. Watch channel (most CONUS) → Ch-13
4. Power → 1 W normal; higher for distress/bend/blind/emergency/non-response
5. VTS → USCG service to prevent collisions, groundings, environmental harm
6. ID → Ship name allowed in lieu of call sign on bridge-to-bridge VHF
7. Relationship → Ch-13 navigation + Ch-16 distress/safety (+ VTS channel in VTS areas)