RedactedNarrative: Vessel Damage for Vessel 1:
  While under tow by a houseboat, vessel 1 was swamped, capsized, and sunk. I was unable to locate vessel in location that it was reported to be tied to rocks in channel on the day of the accident. The following day I was able to locate the vessel still tied off to the shore, upside down and fully submerged.
  
  Property Damage for Vessel 1:
  Vessel owner said they recovered some property that was floating. Unknown other property missing.
  
  SYNOPSIS
  Report of a sunken vessel at Lake Powell that was swamped by a wave while under tow by a rented houseboat. After swamping vessel owner attempted to bail the water, but the vessel then capsized and began to sink. Nearby boaters assisted getting the boat to the side of the channel where it was attempted to be tied off to a rock. Vessel disappeared and vessel owner called NPS dispatch for a report. I located the vessel tied off to the shoreline, upside down and submerged. The authorized and permitted tow company, was contacted and requested to arrange with the owner for removal of the vessel.
  
  ACCIDENT REPORT
  NPS Dispatch requested that I contact a vessel owner about their boat having sunk at Lake Powell earlier in the day. The vessel owner told dispatch that a Ranger had been helping them when it was sinking but had to leave them when a medical was reported. Dispatch had no documentation of this occurrence and no law enforcement ranger from any of the agencies on the lake, had responded. I contacted the vessel owner who explained to me the incident and who requested a report for the vessel sinking.
  
  I met with the Owner family at the rental dock near the stateline boat ramp. They explained what had occurred. They were towing their 21' 1998 Tige boat with a rental houseboat after a week at Lake Powell. Traveling through the main channel near marker 15, they observed a large wave come crash over the towed boat filling it with water. A second wave crashed over the front of the towed boat causing the vessel to swamp. They stopped their tow and began trying to manually bail the water from the boat (see photo), but it soon capsized. Additional boats attempted to assist and they were able to pull the boat to the side of the channel, and tie it to some rocks. They stated they stayed with the boat for two hours, but it became fully submerged. The collected several of the items that were floating in the water, one of which was a bag with the registration and insurance information. The daughter showed me a couple of photographs of the vessel while it was swamped.
  
  FOLLOW-UP
  On 9/6/2020, I returned to the area where the boat was reported sinking. I located the boat and found it tied off to shore where it had been left. The boat was fully submerged and upside down with only the prop of the inboard motor out of the water. Several pieces of the interior seating and padding were on shore near the boat. At the same time the Aramark tow company, the authorized tow service for the NPS at Glenn Canyon, arrived on scene. He stated that his company had been in contact with the owners, and had assisted them on Saturday when the vessel sank. He stated they had been called to recover and tow a different vessel that had capsized at the same location and had recovered that vessel. When the vessel owned by Owner swamped he stated that Owner was upset and frustrated at their situation and stated the boat was not their problem anymore.
  
  NOTICE TO Owner
  I sent an email to Owner advising her the vessel had been located and was recoverable, and that Aramark would be contacting her to recover and remove the vessel from the water.
  
  CONCLUSION
  Vessel 1 was swamped by large waves while under tow causing it to capsize and submerge. The cause of the accident is the rough water condition and large waves swamping a towed vessel in a busy main travel corridor.