Will I be able to hear a noticeable difference with an amp?

Here is my current setup:

Kenwood KDC-MP438U Receiver puts out 22watts RMS to the four speakers

4 - Polk Audio db691 speakers which accept power up to 100watts RMS



If I add in an amp...maybe this one Alpine MRP-F300 which will put out 50 watts RMS to all 4 speakers will I notice a huge change in sound? My end goal is to have the speakers play noticeably louder than they do currently. The speakers are on my boat(not my M3) where there is a lot of noise so the louder the speakers the better. But I'm on a tight budget(trying to spend less than $200) so I'm trying to decide if it is even worth it to add an amp?