house speakers with a car stereo?

I have a pontoon boat, and I am trying to put a stereo in it. And I was thinking about instead of going with a marine 6 1/2" going with a pair of bose 151 outdoor speakers(older model not the se). The price isnt to bad comparitively and the sound quality out of the fully enclosed 151s is alot better. I am worried about ohms and maybe wattage compared to a house stereo. Will it sound close to as well using a car stereo? I dont want to use an amp and those speakers say rated for 40 watts I believe. which doesnt sound like much for a car stereo, but a house stereo 40 watts may be considered more. Any experts on the subject with an opinion appreciated.. tia