Anyone have any creative solutions to preventing or dealing with water splashing out between the lid and tank during stops and starts in my approximately 8 hour trip?
(1) In my more paranoid youth ... i.e., when the fishicle was 200,000 miles younger ... I would sometimes put down an old (but intact) waterbed liner in the back, and use clips on rubber cords to keep the walls upright.
(2) I have re-discovered several times that long coolers positioned perpendicular to the direction of travel have a tendency to tip over if there is a need to make an especially rapid stop. I have a couple of coolers more or less shaped like a 20-L tank that love to turn turtle. If possible, "block the cargo" from front to back to reduce that risk, or at least position long coolers short-edge to the front.
(3) Drive as carefully as possible to avoid rapid stops !!!
(4) Not directly related to the question ... but have you considered how much a 120 qt cooler weighs when 1/2 filled (or more) with water ??? Smaller coolers are MUCH safer to move around when loaded. The +/- 28-qt size, with "over the top handles", can be carried two at a time, like briefcases, without breaking your back.
(5) Belated thought ... packing the fish individually in largish bags, filled with oxygen, solves a lot of problems if you just have a one day trip. Know anybody with an oxygen tank?
HTH
d.d.