Not many of us go to sea to watch television. Yet there is no denying that, at times, it is good to be able to kick back and enjoy our favourites shows.

However, getting good TV reception while away is not always easy. The problem is boats swing from side to side, they face north one minute and east the next and, if they are under way, go up and down as well.

Those with bigger vessels and deeper pockets solve this by installing satellite receivers and these have become more popular as they have got smaller and cheaper.

There is also a new alternative, one that relies on receiving signals from land.

It is a unit called Oceantalk mobile TV and it is available in New Zealand through Lighthouse Marine.

Instead of a satellite dish or a conventional TV aerial, the SUPERdigi comes with twin aerials, married to an inbuilt "diversity" receiver.

As Lighthouse's Mike Harris explains, TV signals come in waves. This is why traditional aerials on moving boats often give poor reception.

"Twin antennas mean that as the waveform rises up or down, one of the aerials is always in the right position to capture the signal."

The receiver samples strong and weak signals and combines them for a consistently clear picture with Dolby-quality sound.

"This means it ensures sharp, high definition TV at anchor, on a swing mooring or flying along at 50 knots."

SUPERdigi costs around $1400, including GST, and will work on all digital terrestrial channels but not Sky channels.