It's simply supply and demand although in this case the supply is 'managed' by various entities to stabilize pricing. It is not a simple model by any means, low oil prices dramatically effect domestic and foreign companies. You would think that with the pandemic, oil demand would be lower and it is but some countries like Saudi Arabia and others have reluctantly started to hold back production to boost market price. In the end, supply and demand will dominate the pricing barring of course artificial factors like tariffs and embargos of imported oil.
With respect to boating, we will see and have seen in the recent past that higher fuel prices tend to shift the boat market to more efficient (aka smaller) vessels. Same thing happened to autos, gas gets cheap and the masses buy trucks and large SUVs.
Yes gas adds and it is east to see the hit since you have to pay to play up but if you look at all expenses like depreciation, finance charge if applicable, maintenance, insurance, storage etc., gas is only one part of the list.
Have you looked at the cost of bait. Last season, some fresh bait costs doubled
Since I don't catch a lot, It seems to me that I am just tossing my money overboard!