Why do they put gas tanks towards the rear of the boat? Seems as if weight would be more evenly distributed if the gas tank were towards the front. Plus this would help to get on plain faster.

I think it depends on the boat. My Glastron had the tank in the bow.

I would guess the first criteria would be that they put it where there's space for it. Most boat bow areas have too little space between the interior floor pan and the outer hull.

There's usually more room in the hull, and they can use the gas tank to offset the weight of things like batteries, etc.

My last boat, the tank was about center - in front of the engine.

Interesting thing though.... some of you may know that Bruce Toran and I have very similar boats. However, mine is an aft cabin version and his is a open cockpit version - same manufacturer.

And we share the same identical hull - the only difference is that the deck comes out of a different mold.

On his boat, both his engines and gas tanks are at the stern. On my boat, my tanks are at the stern, but the engines are mid-ships. I am not sure what the COG differences are between the two boats, but considering the engines likely weigh 1,000lbs each (5.7L), that should be a significant weight difference between the two boats.

While the primary reason my engines are mid-ships is due to having to allow for aft-cabin room, I am not sure how that affects performance between the two designs. But the thought here is two very similar boats from the same manufacturer, and a very different layout of the heavy stuff.

Makes sense since on a cruiser boat handling and speed aren't as important. Amenities and layout wins.

On my boat the tank is centered in front of the engine. I have one 13 gallon waste tank on the right of the engine and one 13 gallon water tank on the left. One battery on each sides too. I love the balance and handling it provides.

For top speed weight at the stern is preferable.

A SBC alone doesn't weigh that much. With a Mercruiser Bravo drive the whole combination is under 1000lbs. But you are correct with a transmission back there, his boat is heavier at the stern than yours.

datkins, you'll find that once you get out of the 17-20' bowrider class, many boats have their tanks under the floor in front of the engine. Mine does.

i would guess manufacturers aim for a boat that has it's weight evenly distributed and since engines are probably the heaviest single parts and are usually located aft, it would make sense to balance that weight foward with something else heavy like fuel tanks, batteries, water tanks, etc. with engine placement more toward the middle, like Al has or the new hulls being designed specifically for IPS type pods and engines have, i would think you'd deliberately want to put weight aft to balance the vessel. personally, i like having the potentially exploding thingies (like fuels, batteries, etc) as far aft as possible since a) it's not udner the cabin when we're sleeping and b) it's not near me when i'm driving. the bottom line it that probably no boat is completely evenly balanced and most need trim tabs, etc to help get on plane. when i see running shots of boats it sometimes amazes me that many boats "on plane" are still dragging their a$$ thru the water.

"i would guess manufacturers aim for a boat that has it's weight evenly distributed"

True for displacement and semidisplacement designs (thus most yachts). Designs that fully plane are a more tricky proposition, balance wise.

As other posts here have said, I think locating the tank on bowriders under the rear of the cockpit is mainly a matter of practicality. The tank is still near enough to where the COG needs to be that it does not make the balance a problem.

Kelly

Shorter fuel lines, 2' vs 20'?

My 34 Sea Ray bridge boat had twins with direct drives and saddle tanks installed next to each engine.

That design made for a VERY stable boat...

My tank is more towards amidships than the rear.. It's in front of the engine compartment which, buy necesity, makes it more amidships than towards the stern.

BillyB; when I guessed the engine weights, I also included the Borg Warner Velvet Drive cast-iron transmissions bolted to the back of them.

Even with an inboard, it still has a transmission.

From BillyB: "datkins, you'll find that once you get out of the 17-20' bowrider class, many boats have their tanks under the floor in front of the engine. Mine does."
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I believe that's where mine is located also. However, because I travel in some shallow waters from time to time and other times I wish to get on plane quickly, I'm wondering about the practicality of manufactures trading the storage locker location with the the gas tank location

See bowriders by Bryant ...

Yep, my Bryant has the fuel tank in the front. Takes a good sized wave to bounce the front when the tanks full. Boat stays nice and level on launch too. I am pleased with it.