A place to start
LorraineThe link gos to Sailnet and a series of engine articles. You're in Kemah. There's gotta be a thousand sailors just on this site from there, so one way is to ask a dock mate.You can also Google diesel engine oil, boat engine oil filters, and any other combination.There are also books written on these subjects, which should be available at a West Marine near you, and maybe even at the library.The most challenging part is figuring out what filters you have, so plan to spend a day or two without an operating engine. Take the old filters off and bring them into a reputable local diesel engine boat related store, and they'll be glad to help you. They'd also probably explain more details than you could find elsewhere. They'll also have a handy dandy filter comparison chart, so you'll know what number filters are right for your engine from more than one manufacturer.Last resort is a mechanic, to show you how to do it so you'll never have to pay them again!

Good luck,Stu