# Surfacing Sub Hits Commercial Vessel **URL:** \ **Category:** Maritime News\ **Created:** [February 9, 2021, 11:18am UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322 "2021-02-09T11:18:28Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![SeaEagle](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/seaeagle/32/17788_2.png) [@SeaEagle](https://forum.gcaptain.com/u/SeaEagle)\ **Post date:** [February 12, 2021, 1:09am UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322/21 "2021-02-12T01:09:00Z")
Lee, you do have to almost surface to use the periscope. You know that. ---
**Author:** ![Lee\_Shore](https://avatars.discourse-cdn.com/v4/letter/l/e9bcb4/32.png) [@Lee\_Shore](https://forum.gcaptain.com/u/Lee_Shore)\ **Post date:** [February 12, 2021, 2:03am UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322/22 "2021-02-12T02:03:30Z")
I expect periscope depth would not be called for until after the area was cleared using the sub’s ability to detect surface traffic prop noise. I doubt state of the art subs rely on blind luck to avoid striking the hull of a ship when rising to the surface. Aren’t those accidents caused more by human error, such as failure to follow procedure rather than lack of information? ---
**Author:** ![dbeierl](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/dbeierl/32/11833_2.png) [@dbeierl](https://forum.gcaptain.com/u/dbeierl)\ **Post date:** [February 12, 2021, 2:53am UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322/23 "2021-02-12T02:53:13Z")
IIRC this was a simulated emergency surface, the kind where the boat comes shooting out of the water for part of its length. I think they may have started from 650 foot depth (too lazy to look it up in the NTSB brief). ---
**Author:** ![Klaveness](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/klaveness/32/7001_2.png) [@Klaveness](https://forum.gcaptain.com/u/Klaveness)\ **Post date:** [February 12, 2021, 7:36am UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322/24 "2021-02-12T07:36:31Z")
> [@WillyJP](#): > > I can tell you that there are quite a few sailors with bar stories about submarines surfacing unexpectedly and alarmingly close aboard It happened to my parents, in a sailing yacht on the Swedish West coast. Technically it happened to me too, but I was too young to remember. They took emergency avoidance on seeing the periscope, which they thought to be an iron post, and didn’t have time to think about where they mis-navigated before the rest of the sub appeared. Complaining to the Navy garnered no response. > [@dbeierl](#): > > I think they may have started from 650 foot depth (too lazy to look it up in the NTSB brief). IIRC, they did a low magnification periscope sweep, but skipped the (slower) high magnification sweep. Anyone interested in passive sonar use should have a dig through Jive Turkey’s analysis section: > **[Sub Brief](https://www.youtube.com/channel/UC9bMgCQyFNaMPsK9GtzM5dQ)** > > Welcome to Sub Brief, I’m Aaron. I’ve spent 20 years serving onboard U.S. Navy submarines. As a U.S. Navy contractor, I provided Strategic and Policy Level consultation for domestic and international clients on cleared Navy projects. Now, I work as... He also did a quick video on this incident: [![](https://us1.discourse-cdn.com/flex016/uploads/gcaptain_maritime_forum/original/3X/3/1/318d1624c649276bd2a07724ff0f003622d36b96.jpeg "Soryu SSK Collision") ](https://www.youtube.com/watch?v=httacbcqfE4) ---
**Author:** ![Kennebec\_Captain](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kennebec_captain/32/13_2.png) [@Kennebec\_Captain](https://forum.gcaptain.com/u/Kennebec_Captain)\ **Post date:** [February 12, 2021, 11:42am UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322/25 "2021-02-12T11:42:23Z")
Wikipedia has a good article. > **[Ehime Maru and USS Greeneville collision | Collision](https://en.wikipedia.org/wiki/Ehime_Maru_and_USS_Greeneville_collision#Collision)** > > Before beginning the maneuvers, Waddle checked the submarine's sonar contacts and noted that there were several surface vessels in the vicinity, but none closer than seven nautical miles (13 km) away. Ehime Maru was one of these vessels. The civilians were spread throughout the control room, with three on the periscope platform and others in front of the fire control station, restricting free access to some of the displays. According to several crewmembers, Waddle, when informed that equip > After completing the high-speed maneuvers, [standing orders](https://en.wikipedia.org/wiki/Standard_operating_procedure) called for the submarine to hold a steady course for three minutes to reestablish sonar contact, which had been disrupted by the high speed maneuvers, with any vessels in the area. In this case, however, Waddle ordered the submarine to change course and go to periscope depth after holding the steady course for only 90 seconds ---
**Author:** ![dbeierl](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/dbeierl/32/11833_2.png) [@dbeierl](https://forum.gcaptain.com/u/dbeierl)\ **Post date:** [February 15, 2021, 3:46pm UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322/26 "2021-02-15T15:46:15Z")
Here’s a good look into submarine sonar from a rocket engineer (Smarter Every Day YT channel). Around 25 minutes. [![](https://us1.discourse-cdn.com/flex016/uploads/gcaptain_maritime_forum/original/3X/e/5/e5308182883132366b2f19236903e458a4def06e.jpeg "How Sonar Works (Submarine Shadow Zone) - Smarter Every Day 249") ](https://www.youtube.com/watch?v=AqqaYs7LjlM) ---
**Author:** ![seasmaster](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/seasmaster/32/3160_2.png) [@seasmaster](https://forum.gcaptain.com/u/seasmaster)\ **Post date:** [February 17, 2021, 2:10am UTC](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322/27 "2021-02-17T02:10:21Z")
However, a first-class sonar man, who had heard the Maru on passive sonar, did not notify the captain of his contact. He testified as such. [Previous page](https://forum.gcaptain.com/t/surfacing-sub-hits-commercial-vessel/58322.md?page=1)