Subwoofer question??

I am in the process of upgrading my stereo system in our 03 supra ssv now I am putting a subwoofer into the boat and have some questions. It seems like I only have room for a sub under the drivers footwell so that is where I am going to put it. the question is what enclosure should I go with to get good bass sound without making it huge. The smallest best bass reponse is the key here. I have been looking at the L5 solobaric 10 in a truck box or I could put a 12 l5 or reular round in a truck box that would be a little bigger. what is the best option going to be. What subs do any of you have under the driver and what do they sound like??

i squeezed two 12"s (infinity perfect 12) in front of the drivers feet by making a custom fiberglass box.

that box must me pretty deep in there. did you take out the wall to under the dash and put it deeper in there? I have a heater installed back there so I'm not sure how much room I am going to have as far as puting a box back there.

yes, i replaced the kick panel with the box. it is also sealed so it only needed 2 cu ft total.

well I ordered the L5 12 solobaric so I will build a box as big as I can for the size I will have back there. It should be an interesting install to say the least. I am getting audiobahn marine speakers they have little horn tweeters in them and have a power rating of 125 watts so it should sound kicken in the boat
Gotta love getting accomodations at my work saving my a lot of money on this install.