Marinemax, the world's largest and most successful boat dealer is in my home town: Miami, FL. I had a chance to visit them in person back when they were located on the Intracoastal Waterway in North Miami Beach.
I was very impressed with their professionalism and cleanliness of their shops, this was many years ago when they only had 2 locations which work out to be around 60 or so stores now? They were located just south of I-95, next to the Dade Marine Stadium where Boat shows are held every weekend during winter season. The second location was closer to downtown Miami at Coral Gables/Coconut Grove area of Biscayne Bay.
When you walk into a marine max store it just looks like a factory, the inventory is stacked up high and all boats are covered with clean coverings attached to the pick-up trucks. It's very impressive and I'm surprised that they don't market this more though it would be great for people who buy their boats and gear there to know how neat and well organized their warehouses are...I always felt comfortable buying my boat parts from them because everything was organized neatly on pallets or racks, nothing was laying around in disarray or dusty which you usually see at other marine shops.
Their prices always came out as good as any other shop, but sometimes cheaper than your smaller mom & pop stores who specialize in one brand such as Yamaha or Mercru. If you have a problem with a part or engine you can always call them up and explain your problem, they will send someone out to help you. And if the part is under warranty then they will either send it to you for free or just come and pick it up from wherever you are to fix it.
Back when I was in college, working summers as a laborer, I helped buy several boats for MarineMax such as 18' center consoles and twin outboards (a Mercury 25's and a very powerful Johnson 40HP).. So I used these two boats since 2006. Every year we would bring them back for inspection and regular maintenance so we never had any major problems with those engines...We never even changed the spark plugs.
MarineMax is the world's largest and most successful boat dealer. Not only do they carry a huge inventory of boats, Marine Max also offers services such as inspections to customers who buy their boats from them.