CONTINUOUSWAVE

[Seeks first-hand information from actual users of] a TrollMaster or iTroll remote throttle control [with an small gasoline outboard engine that does not have remote controls].

See an article in REFERENCE that describes using a non-OEM remote throttle control by TrollMaster:

http://continuouswave.com/whaler/reference/170Auxiliary.html

The author gives information about his experience with a Trolllmaster.

There is really nothing specific to a Boston Whaler boat about either device. They can be used with any small engine on any boat, and for that reason, pursuing this topic on a website that concentrates on angling will likely to expose your inquiry to many more readers who have used either product.