Good Lord! People have absolutely no appreciation of just how vast oceans are, and the Pacific is the great grand-daddy of them all! You can be close to a major sea lane, and by close that might be a two or three hundred miles, and you are still a long way from any help without a radio. Sat-Phone, fine...sure...secure the damn thing...but WTF is your marine radio? Horizon distance is limited by the curvature of the earth and can only be proportionally extended by height, at sea level is just under 3 miles, the height of a ships hull and structures...your vessels height above the water line etc come into play and math is involved...roughly you might spot another vessel 10-12 miles out in daylight and good weather. A quick and dirty calculation is the square root of height/elevation in feet * 1.17. For 6' it is close to the 2.9 mile mark. If the elevation of a ships bridge is 30 feet, then they can see about 6.4 miles, combined they should should spot each other at 9.3 miles. There is refraction and all sorts of other stuff coming into play too, but, basically, the margin for error is really small, and these gals tried to make it smaller...they got lucky...if not for that Japanese fishing boat...