Do you really need a subwoofer in a boat? The short answer is: "Absolutely!". In fact, you need it more than in any other audio environment.
A running powerboat produces a huge amount of low frequency noise, which is impossible for small full-range speakers to overcome. Adding a subwoofer not only gives you better low-frequency output to overcome that noise, but it also makes your main speakers sound cleaner and louder by not forcing them to do extra work in the low-frequency department.
Now that we've answered that question, you will be happy to know that JL Audio's marine subwoofers deliver the kind of bass that has made JL Audio famous in the automotive and home theater sound arenas. This is bass that will impress you, not only with its sheer level, but even more with its smoothness, balance and precision.
Simply painting a car speaker white does not make for a good marine speaker. The marine environment is extremely harsh on a speaker, with huge amounts of UV exposure and corrosive salt in the air and water. The acoustic environment in a boat is also radically different from a car or home environment.
Marine loudspeaker systems and components are specifically designed and tuned for an open-air boating environment, ensuring phenomenal fidelity at cruising speed or while anchored at your favorite swimming spot.