2wd... it's all going to depend on the ramp as to whether you can make it or not. A slippery, slimy ramp can even be tough for a 4wd sometimes. A 2wd... there are times when your truck may need a tow. But again, there's too many variables to say... power-wise - sure, no problem. It all comes to down to traction.
Have you checked your specific truck's (based on model year, engine, rear axle ratio, etc) trailer capacity vs the TOTAL weight of the boat (boat, engine, trailer, fuel, batteries, gear, etc)? Ideally, it's good to be no more than about 80% of max as anything you put in the truck (other then the driver) typically lowers your trailering capacity and the ability for the truck to maneuver/stop well. Notice I didn't say anything about having enough power to pull it - stopping and emergency maneuvering is MUCH more important.