also i put 1 down low on each side up front. you can fit 1 under the water tank but fw of the gas tank and the same on the drivers side. (there's just more room on the drivers side since there's no water tank. center line on the lower speaker was in line w/ the foot rest on both sides... then 5.5" back i believe... i can get you some pictures of that when i get my boat back from having the risers extended.
then i did 2 in the rear facing panel inside the cup holder area in the rear. i did boxes for each one.
then 2 more under the rear seat along w/ 2 square kicker solobaric 12's
including the cabin speakers that's 10 mids for me, i'm also doing 2 alpine PDX series digital class D amps.
here's a pic of the rear speakers in the cup holder area.