If you are saying that the person sent you an Email while 25-30 miles off shore, yes it can happen. Some places you are able to get Cell coverage that far out, using high gain antennasand boosters. One is also able to send / receive Email via satellite almost worldwide. And there is also a way to send / receive Emails via Marine Radio (SSB) or HAM. As to if a sub will 'pop-up' 500 yards from a boat, that one I would not be so sure of :-)

Yep. There have been (rare) cases where a sub has surfaced underneath a surface craft, actually ramming it from below. Usually they are good about avoiding collisions, but stuff happens.

As a retired submariner, I can tell you that YES, it IS possible. However, for submarines, the most dangerous routine operation they do is coming to PD (Periscope Depth) and then surfacing. The CONN is on the 'scope turning 360 degrees continuously during the approach to PD, looking for any signs of surface craft or other floating material during this maneuver. And sonar will be listening the whole time for signs of any powered craft in the area, and fire control and the plotter will be tracking everybody detected, with relation to the ships position. In coastal waters, small boats are much more at hazzard during this time because they are more easily missed. Your friend may have indeed seen a sub surface 500 yards away. But you can be pretty darned sure the officer on the CONN had his *ss reamed by the CO for missing a ship that close if it was a routine surface. If you wanna see a really COOL video of a submarine conducting an emergency surfacing procedure, called an "Emergency Blow", then watch the following video. When you do, keep in mind that this is a Los Angeles class fast attack, 362 feet long and 33 feet in diameter. By comparing the these dimentions to the video, you can see that about 2/3 of the ships length comes entirely out of the water and the keel at the bow of the ship is about two hull diameters or slightly more out of the water. This means the bow of the ship is around 100 feet out of the water, which is ten stories high! Enjoy! . .