Boats, planes, gopeds, racing cars, farm equipment, old cars.
If you arent going to an actual boat/plane/tractor filling station and you just want to, for example, fuel up your goped, you just get regular unleaded and a lead additive and mix them before putting the fuel in the tank.
Turbine engines (jets) do not burn leaded fuels. Jet fuel is similar to kerosene or diesel fuel, with certain additives to meet aviation needs.
The overwhelming majority of piston powered aircraft use 100LL, which has a relatively tiny amount of lead compared to automotive fuels of the 1970s. The FAA has recently certified 100UL for use in all aircraft, but production does not yet meet demand.
Jet-A has higher energy density and is cheaper than 100LL or 100UL, but can't be used in spark-ignition engines.
Compression-ignition ("diesel") piston engines are coming on the market as new and retrofit kits, allowing the use of Jet-A in general aviation aircraft.