I was thinking of mounting the spray arms well aft as per C130/L100 style with the dispersant chemicals carried internally - so you have to penetrate the pressurised hull as part of the STC. Problem is that the Hercy bird is naturally the weapon of choice but finding airframes with the necessary life expectancy is testing to say the least. A good 737 costs 10% of a good C130. Not that I much fancy the idea of 140kts at 100' amongst the seagulls with 2 jet engines!