Jawbone has been teasing its UP3 next generation activity tracker for sometime now. After delays in release its finally going to begin shipping.

Jawbone has said shipping of the UP3 will begin from 20 April in the US and everyone who pre-ordered will finally get their units by mid-May at the latest.

The rest of the world, like the UK, will be receiving the UP3 "later in the year".

Jawbone's UP3 will be the company's first to offer heart rate monitoring built into the wrist wearable. It will also offer more detailed sleep data, detect exercise automatically and will be splash-proof. It won't be waterproof for swim tracking as was originally planned.

On its official blog Jawbone said: "Our intention was to ship an advanced multi-sensor product that defied industry standards with water resistance of up to 10 meters. Unfortunately, after extensive and exhaustive testing we have been unable to guarantee 10 meters of water resistance for all UP3 units." This, it says, was what caused the delay in release.

Jawbone goes on to say: "In the meantime, we look forward to shipping UP3 in the next few weeks in the US and thank our customers for their continued loyalty and patience. UP3 will be available internationally later this year."

READ: Jawbone UP3 with HR monitor, plus budget UP Move model unveiled