oil changes. there has GOT to be a faster way?

just did my second oil change on my '11 LSV. its the first boat ive owned to have the drain tube on the oil pan.

but changing oil is worse than watching grass grow.

i get a tiny 1/16" stream coming out. it takes an hour to get less than two quarts to drain, and then it just goes to dripping. after two hours i can only get less than 3 quarts and there hardly even any drips any more.

motor is fully warm. ive tried everything. park on flat ground, park on huge hill to get some downward slope on the drain tube. ive even tried presurizing the oil pan threw the dip stick tube with my air compressor/tank! tried removing the fill cap. everything. i just cant get more than 2-2.5 quarts out. this has happened both times. its painfull slow. rediculous.

anyone have any tips? or experience with this?

im using the recomended 15W-40 (rottela T)
im thinking about switching to some 5W-30 mobil 1 sythetic for some thinner oil hoping it would drain faster. thoughts? safe?