Here’s a concise, practical guide to reliable marine communications—what to buy by category, which brands/models to consider, plus installation/maintenance and registration tips.

1. Essentials (what every boat should have)

• VHF radio (fixed-mount) — primary short-range voice & DSC distress. Good fixed units: Icom M510 / M605, Garmin VHF 215, Standard Horizon GX2400, Raymarine Ray73. These brands/models are widely recommended for clear audio, DSC and NMEA integration. (maritimeducation.com)
• Handheld VHF — backup for tenders, man-overboard and close-quarters. Look for DSC, float/strobe and decent battery life (Icom M94D, Standard Horizon HX890 are examples). (maritimeducation.com)
• EPIRB (406 MHz) — required for offshore work/passage-making. Choose a modern 406‑MHz GPIRB with GNSS and Return Link Service (RLS) when possible (e.g., ACR GlobalFix V6). EPIRBs alert SAR authorities via Cospas‑SARSAT and are life-saving equipment. (fisheriessupply.com)

2. Beyond VHF/EPIRB — for longer range, tracking and redundancy

• AIS transponder/receiver — AIS Class A (commercial) or Class B SOTDMA (pleasure craft); recommends Vesper / Garmin / Simrad / Garmin AIS800 class equipment. Note: after Garmin’s acquisition of Vesper there have been product-line and support changes discussed in the marine press — factor current support/firmware status into buying decisions. (panbo.com)
• Satellite communicators (two-way text, SOS, weather): Garmin inReach family (Mini 2, Messenger Plus) and alternatives like ZOLEO, Somewear and Iridium-based products. Garmin’s inReach Messenger Plus adds photo/voice messaging to two-way satellite texting and an SOS service. Choose portable units for crewmember carry or installed Certus/Sailor/Cobham terminals for full-boat data/voice. (garmin.com)

3. Typical recommended devices (examples)

• Fixed VHF: Icom M510 / M605, Garmin VHF 215, Standard Horizon GX2400. (maritimeducation.com)
• Handheld VHF: Icom M94D, Standard Horizon HX890. (maritimeducation.com)
• EPIRB: ACR GlobalFix V6 (406 MHz GPS, RLS, NFC/app diagnostics). (fisheriessupply.com)
• Satellite messenger: Garmin inReach Messenger Plus or inReach Mini 2 (for two‑way messaging, SOS, weather). For installed satellite broadband/voice, Iridium Certus terminals / Cobham Sailor products. (garmin.com)
  (Note: pick devices that match your cruising range and budget; small coastal boats often pair a VHF + handheld + PLB/small satellite messenger; offshore vessels should add EPIRB + dedicated satellite terminal.)

4. Buying & installation tips

• Antenna quality and placement matter as much as the radio: low-loss coax, proper grounding, and an elevated, unobstructed VHF antenna will dramatically improve range and reliability. (Installer/yard shops can advise specific mounts and feed-throughs.)
• Power and redundancy: hardwire fixed VHF to a fused circuit and provide a dedicated backup battery or reliable charging. Keep a charged handheld VHF on board at all times.
• NMEA / chartplotter integration: if you want DSC distress, AIS overlays and autopilot/MFD integration, choose radios and AIS transponders with NMEA 2000 or NMEA 0183 compatibility. (borrowaboat.com)
• Professional installation for satellite and AIS: certified installers ensure proper antenna grounding, coax runs and configuration (MMSI programming, transponder class settings).

5. Legal/registration & subscriptions

• Register your MMSI for any DSC-capable VHF or AIS transponder (your national authority / FCC in the US). Your AIS transponder typically must be programmed with a correct MMSI before transmitting. (support.vespermarine.com)
• EPIRBs must be registered with the appropriate national SAR authority (e.g., NOAA/USCG in the U.S.).
• Satellite devices require airtime/service plans; compare subscription tiers (SOS coverage vs two-way messaging vs data/voice). Garmin inReach devices use Garmin plans; Iridium/Cobham Certus requires separate airtime contracts. (garmin.com)

6. Maintenance & checks

• Test handheld VHFs monthly and carry spare batteries/charging cable.
• EPIRB: follow manufacturer inspection schedule, replace batteries per expiry and test per approved procedures; check bracket/hydrostatic release if required. (fisheriessupply.com)
• Keep firmware up to date (radios, AIS, satellite terminals) but check release notes—major updates sometimes change interfaces or app support.

7. Budget guidance (ballpark)

• Handheld VHF: ~$150–$500.
• Fixed VHF: ~$300–$900 (higher for integrated VHF+Ais or chartplotter connectivity). (maritimeducation.com)
• EPIRB: typically $400–$900+ depending on features (GPS, RLS). (fisheriessupply.com)
• Portable satellite messenger: $200–$600 device + monthly service ($10–$50+/month). Installed satellite terminals (Certus/Sailor) cost several thousand plus airtime. (garmin.com)

Quick checklist before you buy

• What range do you need (coastal vs offshore)?
• Do you need two‑way global text/voice or only SOS?
• Do you want AIS receive-only or full Class B transponder transmit?
• Can you get professional installation and local support/warranty service?
• Will you register MMSI/EPIRB and budget for subscriptions/maintenance?

If you want, I can:

• Narrow recommendations to a specific boat size/use (e.g., trailerable coastal dayboat vs bluewater cruiser vs commercial workboat) and budget, or
• Give a short shopping list (models + approximate US prices and links).

Which of those would be most helpful?