Your local boat dealer will have an oil changer that has a tube that goes in the dip stick and sucks oil out of the engine, Its real easy. By the way make sure you start the engine and get the oil hot first.
Probably the best way you can possibly drain the tank is to purchase a siphon pump hose and drain the gas into containers. I hope the tank is less than 1/4 full, because that is a LOT of gas to drain! GLiDE
remove the plug in the rear of the boat! and let it drain. if you don't have a drain plug,you will need to get a bilge pump. wal-mart has a good selection of them and they are cheap.
A "bilge pump" is not automatically on a boat. Every boat does however have a bilge area. It is the area in a boat's hull where water collects. This area is seriously recommended to have a "bilge pump" in it on every boat to pump the water out of this area while on the water. Bilge's have drain plugs on the back of the boat for when you take it out of the water to fully drain it.
Insert the drain plug.
Insert the drain plug.
drain plug
Easiest way is with an electric pump through the dipstick tube. This works best with warm oil. Shur-Flo pumpbuckets are available online or at most marine stores. Most centurions had an extension tube to a fitting on the oil pan. You run that tube through the bilge drain (with boat on a trailer), and then take the plug out of the extension tube.
The heavier the boat is loaded, the deeper in the water the boat will float.
The best time to buy a boat is in the winter.
BOAT seems the intelligent answer
I feel The Austal 102 trimaran is the best boat in the world
A free jet boat.