zenspector wrote:...I was just wondering, why such a large tank?
I think you are asking about the 190 MONTAUK. The tank capacity is probably a result of making use of the space available in the hull. The designers probably had a certain amount of space in the hull for a tank, and they just filled that space. That gave them the tank capacity.
Or maybe they already had a 60-gallon tank used in some other boat, and they fitted it to the 190 MONTAUK. That keeps down the number of parts in inventory.
If you look at historical fuel tank capacity in other Boston Whaler boats, you find:
OUTRAGE 18 = 63-gallon tank
OUTRAGE 19 II = 70 to 80 gallon tank (varied)
OUTRAGE 20 = 77-gallon tank
OUTRAGE 22 = 77-gallon tank
OUTRAGE 25 = 140-gallon tank
Considering today's outboard engines get much better fuel economy, I suppose you could make an argument that 60-gallons is more like 80 or 90-gallons of old. And, yes, having 13-hours of endurance is a lot of fuel capacity. But, on the other hand, you don't have to keep the tank filled to the brim all the time.
I don't see the 60-gallon tank on a 190 MONTAUK as a drawback. For one thing, if you come across a good price on fuel, you can put a lot of fuel in the tank. My truck has a 42-gallon fuel tank. It comes in handy when you find gasoline at a good price.