I have a boat with a diesel in it, so I know the value of clean fuel tanks and filtered fuel. OK I'm thinking of adding a dual in-line filter/water separator. to my 97 5.9 Cummins 12 valve. My question is it worth it or is it over kill? Since I live on a pension and some of the rigs I've seen are about $300.00 I don't want to waste money, but I do travel thru Mexico from time to time so,if I need it I'll get it. What do you think? Pros and cons please.Also if possible would you recommend a manufacturer, model ,etc?

Thanks in advance