Each person who buys a boat usually has to make a decision early on about what type of oil they’ll be using in the boat. Of course, part of this decision is made for them purely in the type of motor the boat has. If the boat has a two cycle motor, then your options are limited to oils that are rated for this type of outboard motor. Beyond this, there are many brands of oil to choose from.
When my cousin first bought a boat that had a Yamaha motor on it, he started to look for oil that he could use in the motor. The natural decision for him was to buy Yamalube brand oil, because the brand was from the same company as the one that had manufactured his boat motor. This was logical to him because that company should know what oil formula would work best for a motor that they made.