Lowrance Endura Sierra

£500 + £100 for 1:50,000 National Parks
Weight: 242g (inc batteries)
Size: 13x6x3cm
Battery life: 10-15 hours
Channels: 42
www.lowrance.com

+ Clear mapping detail on screen and easy to use. Good satellite coverage. Some excellent additional features including the combination of touch screen and buttons to navigate. Shockproof and submersible.

– The 2.7inch screen is small. Expensive.

Verdict: Their top of the range unit features a rubber-cased waterproof unit that includes an MP3 player, Microphone and barometric altimeter. The only unit to encompass touch screen and button operation. For the price we found the performance a little disappointing.