The short answer
A marine VHF signal travels roughly in a straight line, so the curve of the earth sets the limit. A common rule of thumb gives the range between two antennas as:
Range (nautical miles) ≈ 1.23 × (√h1 + √h2), with antenna heights in feet
Formula as taught for marine radio operators (open-exam-prep, RYA SRC study guide). Transmit power, antenna quality, weather and sea state all reduce it in practice.
| Link | Antenna heights | Approximate range |
|---|---|---|
| Center console to center console | 9 ft and 9 ft | 1.23 × (3 + 3) ≈ 7.4 nm |
| Boat to a tournament base | 16 ft and 100 ft | 1.23 × (4 + 10) ≈ 17.2 nm |
| Tower boat to a tournament base | 25 ft and 100 ft | 1.23 × (5 + 10) ≈ 18.5 nm |
| Handheld to handheld | 6 ft and 6 ft | 1.23 × (2.4 + 2.4) ≈ 6 nm |
Why that matters in an offshore tournament
An offshore boundary can run fifty to a hundred miles or more. Past twenty miles or so, a boat calling a catch on VHF is heard only by boats near it, and the call reaches the committee — if it does — relayed boat to boat. The director hears it late or secondhand, and the dock and the spectators hear it last, often at weigh-in.
What NautiSignal changes, and what it keeps
| VHF alone | With NautiSignal | |
|---|---|---|
| Reach | Line of sight, roughly 6–20 nm | Wherever the boat has satellite Wi-Fi or cell signal |
| Who hears a catch | Boats within range | The committee, every boat on the channel, the dock and spectators — live |
| The record | A logbook and memory | Server timestamp, GPS position, confirmation code and acknowledgment |
| Disputes and ties | Recollection of radio traffic | Sorted by server seconds |
| Distress | Channel 16 to boats and the Coast Guard in range | Channel 16 still first — plus the director and nearest tournament boats alerted with your position |
NautiSignal keeps VHF in the loop. Tournament announcements, lines in and lines out, and official catch confirmations are broadcast over marine VHF from the director’s console, so every boat with a VHF hears the tournament — with or without a NautiSignal device. And VHF Channel 16 remains the first call in any emergency.
NautiSignal and scoring apps
Scoring and leaderboard apps tally results. NautiSignal is the communication layer underneath: live voice, catch reporting with timestamp and position, director confirmation and safety. It works alongside your scoring system — every catch exports in receive order with the official tie-break sequence.
See how far it reaches: Starlink for boats and the tournament radios.
Hear every catch, wherever the fleet fishes.
Tell us your boat count, dates and format and we’ll build the right setup and a per-boat quote.