From Watkins Landing down to Boshers dam you can use any kinda boat bc its deeper in that section alot deeper then above watkins. I say about 2-3mi up from watkins you will start to hit rocks, rapids , and riffles and gets REALLY shallow. I wouldnt recomend a fiberglass boat or larger bass boat above watkins as thats when starts to get shallow and get into some rocks. If you had a jon boat or one of those rhino jet bass boats you can manuver your way up river. Now maidens landing , west view and on up i DEF wouldnt recomend a large bass boat! Only jons, canoes and yaks bc its SHALLOW as in stand in middle of river ankle deep shallow in some parts! So yes below watkins you can fit bass boat and go down river fine. But up from watkins i would go with jon boat or something like that. Its amazing to see those rhinos jet bass boats just rip right up rapids in just inches of water!
Hope this helps and good luck!