Haudenosaunee navy are extremely limited, and have only one 20% upgrade to help 'em. Their best unit, the War Canoe, is roughly 1/3 the cost of a frigate, but only has 1/6 of the HP, and 1/4 of the attack power. Yeah, you can make 10 of 'em, but a whole fleet gets absolutely decimated by just two frigates, so God forbid the enemy also has caravels and monitors to supplement their fleet; you could ruin yer economy absolutely spamming boats, and they’d just get demolished in 2-3 attacks as they get made.
Plus, they don’t have forts or any equivalent, and war huts are completely helpless against even a single monitor… Haudenosaunee just automatically lose on water maps, they have no way of defending theyselves or gaining any ground.
They either need some sort of dedicated anti-ships building, or a serious buff for their canoes; whether it be a severe cost reduction (cut in two, at minimum) and/or a damage bonus against ships; it’s just not normal to require a full (and expensive) fleet in order to bring down a single enemy ship