Polar - M430 GPS Heart Rate Monitor Watch

If the wrist HR monitoring on the M430 is not accurate enough (or not at all accurate according to some reviewers) is there an option with the M430 watch to use a the Polar chest strap from the M400 (that I have used for about 3-4 years) to monitor HR??

I can't afford a power meter so I needed a reliable and accurate HRM for training. I mostly ride but also trail run and strength train to mix up my workouts. I've used Polar products since 1991 always had good luck, especially from a durability perspective. I did my research on other GPS HRM's but found the m430 to be the best watch for the price. It might not have all of the features of other units but I went with a known product vs something new.

This watch appeared to do everything I want it to, so I upgraded from the M400 for the wrist-based heart rate monitoring.. However, the GPS implementation is not up to par with other watches, such as the Rip Curl SEarch GPS. I use the M430 for surfing and the GPS signal gets lost even when my hand is a few inches under water. Because paddling requires dipping the hand in the water every second or two, the vibration and visible ""GPS signal not found" alerts are almost constant. Nevertheless, after my surf session, the GPS map showing where I paddled and rode waves seems fine. I would love it if they would make reception of the GPS signal strong enough to travel through at least a little water, however I understand there may be technical challenges beyond their control. Still, the RipCurl Search does not seem to suffer from the same weak GPS signal reception.