Marina Wireless Bridge — Marlborough Sounds

A marina in the Marlborough Sounds had no broadband — the office relied on a cellular hotspot that dropped out whenever a cruise ship blocked the nearest tower. The nearest fibre termination was 2.3 km away on the far side of a bay, with no direct line of sight. Terrain on both sides was DOC-managed bush; trenching fibre was not an option.

The problem

The marina office needed reliable internet for EFTPOS, weather feeds, booking enquiries and staff communications. The cellular hotspot was costing them bookings — customers couldn’t reach them reliably, and EFTPOS timeouts during peak summer were losing revenue.

Terrain and survey

A site survey with binoculars and a drone confirmed that a near-line-of-sight path existed between a high point on the marina side (a pole mount on the office roof) and a tree-cleared knoll on the far side where a farmer had consented to a small pole. The path crossed 2.1 km of open water and 200 m of low scrub; the Fresnel zone clearance was tight but workable with 5 GHz gear.

Equipment and install

We specified a pair of Ubiquiti airFiber 5XHD radios with 30 dBi dish antennas — the high gain and narrow beamwidth were necessary to punch through the partial obstruction. Power came from PoE injectors at both ends; the marina side had existing solar+battery, and the far side needed a small standalone solar panel and charge controller. The install was done over a single weekend: pole mounts on Saturday, alignment and commissioning on Sunday.

Commissioning result

After alignment (using the built-in alignment tool on the radios), the link locked at 450 Mbps aggregate with a -62 dBm signal — well within spec. Latency was stable at <2 ms. The marina office now runs EFTPOS, VoIP, a guest WiFi network and cloud-based booking software over the link, with the cellular hotspot kept as a failover.