fuel tank advice needed please

[erikserras]

hello all,
i have a 1970 43c with 3 factory tanks. the two aft tanks have been filled with water for many years by the previous owner and the boat operated from middle tank. i believe they are 200ish gallons each. boat power is 8-71tis.
i just had the tanks emptied and 3 tanks polished the two aft tanks were spotless and wiped down by hand. 3/4 tank fresh fuel was added to all tanks and boat taken on a 20 plus mile trip in rough water. first the raycors were filthy. changed filters then they were filled with emulsified fuel/water. the center tank fuel is clean with no issued. the both aft tanks are completely emulsified water/fuel. checked with fuel dock and their fuel is clean, fuel polisher came and drained the fuel again in aft tanks as it was the best option. my plan was to take the boat out with small amount of fuel in each aft tank and see what the raycors tell us.
what are your thoughts? .are the baffles filthy and debrit shaken loose from fuel and bumpy ride, algae in baffles acting like a sponge and held alot of water and mixed during the ride? etc. these are things that were suggested to me. any other thoughts on how water gets into a clean tank with fresh fuel?
any help would be great. thanks as always

 

[Pascal]

Could some water have remained trapped at the bottom behind baffles away from the access plate? Deodorant on the angle of the boat at rest, water could be inaccessible at rest but then move forward or aft as the boat pitch changes underway.

 

[Captain Ralph]

Yep, Just some hidden / trapped water.
Anybody blow out the fuel lines, vent lines, return lines and pickups?
Ah, I still maintain a small nitrogen bottle just for these things.

 

[erikserras]

lines were cleaned and blown out.
could there be enough water trapped to emulsify with 150 gal of fuel after 20 miles in rough water in both tanks?

 

[Boatsb]

Emulsified would point to mixed under pressure like a fuel cooler failure. How much came out? How much extra was there from the water.

 

[Avenger]

All the O-rings on the deck fills were checked? Vent plumbing isn't compromised, has proper anti-siphon risers? Do the engines have fuel coolers?

Not knowing the history of the boat you have give everything.a good look-over.

 

[rsmith]

They put 8/71 ti in a 43c?

 

[JuiceClark]

They put 8/71 ti in a 43c?

Hmmm. I could see downsizing to one of those.

 

[erikserras]

Hmmm. I could see downsizing to one of those.

yep 18kts at 2100