Fuel Bladders on Bow

200 gallons makes that first fat 1500 pounds. Double the fuel, then a real fat 3000 pounds.
1.5 tons.
Ouch.
Not mentioned is if a davit or tender is already up there.

I don't think I'd put much more on the bow. You could try another 200 gallons. I hate bladders on the bow as they are very hard to empty in any kind of sea state other than calm. I know you can carry a ton in the cockpit and prefer 55 gallon drums as they have a much smaller foot print than a bladder.

Just curious, do you need the extra fuel routinely or is this for a one time extended voyage? I can't imagine dealing with bladders and fuel transfer out of them as a routine event.

That would suck to have use a bladder, much less multiple bladders as a routine. I'm assuming you've exhausted all options of adding another fixed tank somewhere or increasing size of the existing tanks?

I can see wanting to limit the cost given you are not keeping the boat. Hopefully you will post info here when you move up to a 60'

Just curious how much you burn on the 120 mile round trip. I make a similar run occasionally fishing in NE Canyons. I usually burn about 700-750 Gallons on a 53 Viking. I don't really push it very hard on the trip usually 22-23 kts.

We do a similar trip several times a year but we run at about 8.5 knots except for when we slow down to troll. It's 130 miles from our house to the oil rigs and we typically burn around 400 gallons on the 4 day trip.

Curious, do you actually save on gallons per mile at 22-23 kts? In my 54' I don't really save anything once I get above about 11 kts. I actually save a little gal/mile going a little faster and pushing to 80% load. I believe this is due to more stern lift at higher speeds. I do save a lot if I'm willing to slow to 8-9 kts however. 12-14 kts is my worst speed for gal/mile. I believe the hydrodynamics are similar for most sportfish boats although the exact speed where things change will obviously differ somewhat depending on length and hull characteristics.

I Don't have enough real data to say for sure but anecdotally it seems to save some $$$. Cruising to Block Island when I was in a "hurry" I definitely burned more. I average about 53-55 GPH at 22-23 (1950 RPM) I average 61-63 at 2050 but I only gain 1.5-2 knots. I have mechanical engines so maybe they aren't as linear as common rails. I'm pretty happy with the efficiency. I hold 1100 gallons, so I always felt that was enough reserve. to OP why do you want to carry that much extra fuel and weight?

Why slow down to troll???? Lures will pull and work just fine at 8.5 knots on your way in and out!