Many High quality GPS/Chartplotters will work as you want. However you will need to reset some peramiters. Most units are set to take a reading every 1-3 seconds. This is not going to give a very accurate acceleration and top speed acheived in a drag race. ect. Change the signal pick up to the quickest, in our case with a lowrance we can resett to every .2 seconds. I would think some more modern units can get as close to .1. This is ever 1/10 of a second. Oh, use a high quality unit designed for outdoor use. I have much more experiance with Lowrance products than any other. Easy to operate, water proof and extreamly durable. Units are available from Baja to boats, to hiking. We use the boating/marine units. Both shock and water proof. Al