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The SV Avrio was initially sighted by the US coast guard on 27 January at 01:27 local time (06:27 UK) 71 nautical miles from Ocho Rios which is in on the north coast Jamaica.

The Jamaican coast guard was alerted and arrangements were made for the vehicle to be brought to Port Antonio which is located in the northeast of the country.

There is a deceased person on board. Jamaican authorities are investigating.

The family of Mark Brenan wishes to thank everyone who helped in this search.

Fourth Update January 8, 2020

Chris Parker, Marine Weather Center, has provided a new drift analysis for SV Aviro as follows:

Let’s assume a position December Sat28 evening = 15-40N / 74-30W.
From Sun29 onward….
Currents remain fairly significant, flowing 255T about 1.2k on average to 76W…while wind Sun29-Tue31 was 070-080@17, so drift from wind should be to 255T about 0.6k…suggesting vessel should move about 255T@1.8k, and should cross 15-15N / 76W about Midnight Tue30 night.
From 76W to 77W currents decrease significantly, with an average motion to 270T only about 0.7k. Wind also abates, blowing from about 070T@14 Wed1-Thu2 , which should cause drift about 0.4k….combine set & drift = 1.1k on course 265T, so Thu2 afternoon (40 hours after Midnight Tue30 night) the vessel would be near 15-15N / 76-46W.
Wind strengthened significantly Thu2 night, as did current….so from about 76-46W to 78-30W, current averaged 285T about 1k….and wind was 080@20 Thu2 night, 080@18-20 Fri3, and 090@17 settling to 090@15 Fri3 night, and continuing to drop to 070@12 by Sat4 evening. Let’s say average wind in this interval 082@17, suggesting drift from wind 0.5k in direction 262T. Net motion then is 282T about 1.4k, which over 60 hours from Thu2 afternoon to Sat4 overnight = 84 mi, placing vessel near 15-44N / 78-06W Sun5 at Dawn.
From here, things get more complex, since wind & current were very different directions, and therefore if we’re wrong about the portion of motion due to each, there’s a much larger error in resulting course & speed.
Current from 78-06W to 78-30W is toward 290T about 0.8k (in 36 hrs = 28 miles) . Wind Sun5 is 030@18, resulting from a ColdFRONT which pressed into the area Sun5 morning. Wind was short-lived, settling to 040@10 by Sun5 evening-Mon6. Let’s say average drift due to wind toward 210T at 0.6k for 12 hrs, then 220T at 0.2k for 24hrs, for a net of 13 miles toward 213T. Combining set from current and drift from wind nets out to about course 257T for 32 miles for 36 hrs thru Mon6 afternoon, placing vessel near 15-37N / 78-38W Mon6 afternoon.
From 78-38W to 79W current is weaker and more uncertain, but probably flows toward about 255T averaging 0.7k. Wind averaged 070@14 for 24hrs from Mon6 afternoon-Tue7 afternoon, resulting in 0.35k of drift, so in 24hrs the vessel should have moved 25 miles in direction 254T, placing vessel Tue7 afternoon near 15-30N / 79-03W.
From 79-03W to 80W current flows toward 230T at 0.5k. Wind has been building gradually due to another ColdFRONT, and will average from Tue7 afternoon-Thu9 afternoon 060@20, with drift from wind toward 240T about 0.7k, and a net motion of 1.2k toward 234T for 48 hrs, making estimated position Thu9 afternoon: 14-55N / 79-50W.
Wind will be very consistent Fri10-Mon13...averaging 080@25, which is stronger than any wind the vessel has experienced thus far in the month since it departed Grenada…let’s assume this results in a drift due to wind of about 0.9k in a direction of 260T.
For 40mi from 79-50W to 80-30W there’s little current, flowing on average 260T near 0.3k…for a motion of 1.2k (0.3k current + 0.9k wind)…at Midnight Fri10 night the vessel should pass near 14-48N / 80-30W.
From 80-30W to 82W current flows on average 0.8k on course 340T…while wind continues drift component 260T about 0.9k. Resulting course over ground 298T at 1.3k….so at Midnight Mon13 evening the vessel should be near 15-32N / 81-56W.
Of course, only slight errors in speed and directional component from current and wind amplify over time, and since it has been 18 days since the last confirmed sighting, the vessel could easily be in a location 100 miles from where we expect.
We expect the vessel traveled a somewhat indirect route covering about 600 miles due-W in 18 days, or about 33mi/day, for an average speed of 1.4k.
This speed is very similar to the verified speed of 1.5k in the 13 days from departing Grenada to the 1st verified sighting, so I think our estimates are sound…but there is uncertainty.


Third Update December 31, 2019

UPDATE: 31 DEC 2019 10 AM
RCC Jamaica is conducting flights to try and locate SV Avrio.


Second Update December 28, 2019

Drift Analysis by Chris Parker, Marine Weather Center

Vessel supposedly departed Clark’sCourt Marina in Grenada (12-01N / 61-44W) Friday Dec 6, about 19:00 AST.
RCC Curacao #1:
19 dec 22.10 LT (20 dec 02.10Z) 14-30.03N / 069-23.26W
Elapsed time since beginning of voyage = 13 days + 3 hours (315 hours).
Nautical miles since beginning of voyage = 473 miles, course 289T
Average speed = 1.50k
Set from current:
Average SeaSurfaceCurrent = 0.7k, flowing toward about 290T, which over 315 hours = 220mi.
Wind-driven drift:
Wind was very steady Fri6 night-Wed11 (5 days) 070-080@15-20, vessel should have drifted on course 260T@1k to 1.5k, covering 120-180mi in 5 days.
Thu12-Fri13: wind 090-100@10-15, vessel should have drifted on course 280T at 0.5k to 1k, covering 25-50mi in 2 days.
Sat14: 090@15, drift 270T@0.75k, covering 20mi in 1 day.
Sun15-Thu19: 090@20, drift 270T@1.2k to 1.5k, covering 120-150mi in 4 days + 3 hours.
Total distance over 315 hours due to drift from wind: 285-400 miles.
Adding set from current and drift from wind suggests vessel should have drifted 505-620mi in 315 hours, for an average speed of 1.60k to 1.96k.
Since the vessel moved at 1.50k, we can presume I am overestimating either the current set or the wind drift, or both…or maybe the vessel is towing docklines, as someone commented it appears from one of the RCC Curacao pictures (or has a foul bottom), and is therefore drifting with wind more slowly than a typical sailboat.
Conclusion: the vessel could have gotten where it is had it drifted there from Grenada, with zero human intervention. Also, the vessel is probably drifting at the very low end of the range of estimated drift due to wind.
RCC Curacao #2:
20 dec 11.10 LT (20 dec 15.10Z) 14-41.06N / 069-39.65W
From RCC Curacao #1 to RCC Curacao #2:
Elapsed time = 13 hours
Nautical miles covered = 19, course = 305T, average speed = 1.46k.
SeaSurfaceCurrents: 0.9k, flowing toward 315T
Wind 090@20, presumed drift from wind 1.5k course 270T.
Conclusion: given that direction of motion is very close to but just S of direction of current, I think the vessel is drifting about  50% of the low end of my drift speed….so even in 20k of E wind, the vessel was probably drifting W at only 0.6k due to wind, and drifting NW at 0.9k due to current.
RCC Curacao #3:
21 dec 21.00 LT (22 dec 01.00Z) 14-56.00N / 070-32.50W


From RCC Curacao #2 to RCC Curacao #3:
Elapsed time = 34 hours
Nautical miles covered = 53, course = 286T, average speed = 1.56k.
SeaSurfaceCurrents: 0.9k, flowing toward 290T
Wind 090@20, presumed drift from wind 1.5k course 270T.

Conclusion: assuming WNW set from current at 0.9k, then W drift from wind is probably 0.7k, which is about 50% what I would normally estimate for an average sailboat adrift in 20k sustained winds.

Where do we go from here?
Set from current is probably about 50% of the total speed of the vessel.
Set from current predicted as follows:
2.5 days from Sat21 evening-Tue24 morning: current flows 270T about 0.7k = 48mi in 60 hours…PLUS wind E@20 causes 0.6k drift to W = 36mi in 60 hours. TOTAL = 84mi on course 270T, which places vessel 14-56N / 72-00W Tue24 morning.
From Tue24 afternoon-Thu26 evening an approaching ColdFRONT suppressed wind, which settled from E@20 to E@10, and current drifted NW a bit faster…so in 60 hours Tue24 afternoon-Thu26 evening: current flows 320T@1.1k = 66 miles….and drift from wind = 0.4k to the W, or about 24mi, and an average course of about 305T for 85mi, or a position Thu26 evening = 15-44N / 73-15W Thu26 evening.

In the 48hrs since Thu26 evening…current is flowing W@1.2k = 58mi…and wind has rebuilt from ENE@10 to ENE-E@18, suggesting wind drift 260T@0.3k, or about 14 miles, and an average course of about 267T for 71 miles, or a position Sat28 evening = 15-40N / 74-30W.

From Sun29 onward….
Currents remain fairly significant, flowing W about 1.1k on average to 76W…while wind is 080@17-20…suggesting vessel should drift on course about 267T@1.5k, and should cross 15-35N / 76W about Tue31 morning.
From 76W to 80W currents decrease significantly, with an average motion to the only about 0.4k. Wind also abates, blowing from about 070T@10-15, which should cause drift about 0.4k….combine set & drift = 0.8k on course 260T, so it may take 3 days (until Fri3 morning) to cover 58mi to 15-24N / 77W.
Wind should be a bit stronger Fri3-Sat4, maybe 090@16-20, so let’s assume 0.4k from current and 0.6k from wind to cover 58mi in 60 hours to reach 15-24N / 78W late Sun5.
From 15-24N / 78W late Sun5 it’s about another 300mi W to the Honduras-Nicaragua border, which at 1.3k could take another 10 days, getting us to January 15.
If we see more N-NE wind due to ColdFRONTs, then the vessel may make landfall along Nicaragua  in 2nd half of January (if it does not run aground on any reefs / islands before reaching Nicaragua).
Another option is if wind is mostly E-ESE, and currents which from 80W to 81W flow N-ward then WNW into the NW Caribbean catch the vessel, then it may approach Mexico at the end of January / early February.
Hope this helps…Chris.
Chris Parker

Weather Forecasting & Vessel Routing
Weather & Communications – Hardware, Software, Sales, Consulting, Books,
Marine Weather & Communications LLC (and dba Marine Weather Center)
5130 Medulla Rd
Lakeland FL 33811
ph 863-248-2702
fax 863-248-4666

First Update December 28, 2019 – Positions of SV Avrio Corrected by JRCC Curacao

Updated Boatwatch on SV AVRIO with MARK BRENAN aboard.

All cruisers in the area of the Caribbean highlighted in red should keep a sharp lookout for the SV AVRIO and assist if possible to determine if MARK BRENAN is aboard the vessel.



On 16 DEC 2019 received a missing boat report from a cruiser aboard a boat at Clarkes Court Marina, Grenada. That cruiser was worried about a dockmate at the marina named MARK BRENAN aboard the SV AVRIO.
MARK BRENAN was observed driving his boat out of the marina on 06 DEC 2019 at approximately 2000 hours. It was dark outside, and his navigational tri color masthead light was functioning. MARK BRENAN had arrived in Grenada from Barbados on 02 DEC 2019, and prior to that crossed the Atlantic Ocean.
The ocean crossing was hard on both MARK BRENAN, who is still a somewhat inexperienced sailor. The S/V AVRIO had dirty fuel issues, no radio or cellular telephone, and he had lost his dinghy in the trans-Atlantic crossing.
Subsequent investigation by has identified the S/V AVRIO as a Halmatic 30, blue hull, with “TYC” on the stern. TYC stands for the Thurrock Yacht Club in Essex, UK that listed the S/V AVRIO. Previous owner was Brian Clarke of Thurrock YC. Thank you to Boat Watch members in the UK for tracking this down.
On 19 DEC 2019, a SAR aircraft from RCC Curacao spotted a vessel adrift at 22:10 local time or approximately 126 NM NNE of Aruba. They took a photograph of the vessel as shown below.
This information was forwarded to JRSC San Juan who had seen the BOLO for the S/V AVRIO, and connected the dots that this adrift vessel was the one missing from Grenada on 06 DEC 2019.

The vessel was spotted by JRCC Curacao as follows:

19 dec 22.10 LT (20 dec 02.10Z) 14-30.03N 069-23.26W

20 dec 11.10 LT (20 dec 15.10Z) 14-41.06N 069-39.65W

21 dec 21.00 LT (22 dec 01.00Z) 14-56.00N 070-32.50W


RCC Curacao calculated the vessel drifting on a 286-degree course at 2.4 knots. It is believed that JRCC used thermal imaging with negative results.
RCC San Juan assisted JRCC Curacao in issuing an AMVER Message regarding the vessel requesting ships in the area to render assistance if possible. There were no responses from ships in the area. then focused on locating the next of kin for MARK BRENAN. Boatwatch made contact with MARK BRENAN’s Brother In Law and Mark’s Mother, both living in the UK.
A missing persons report was filed by the family of MARK BRENAN with the police in the UK.

On 27 DEC 2019 Detective Constable Alison Hayhoe, Southern CID
M: 07885264407, E-mail contacted to advise that anyone with information regarding MARK BRENAN or the S/V AVRIO should contact Detective Constable Hayhoe at the aforementioned phone number and/or e-mail address. has asked Chris Parker of the Marine Weather Center to conduct a drift analysis of the SV AVRIO based on the positions provided by RCC Curacao. It is our hopes at, the police department in the UK can prompt some Rescue Coordination Center in the Caribbean to try to locate the SV AVRIO. MARK BRENAN may be incapacitated or injured and aboard the vessel. will continue to monitor this case until a resolution is made. Any information regarding this case may also be sent to We thank the many cruisers in Grenada and elsewhere who have assisted in this boatwatch. It’s all about Cruisers Helping Cruisers.
Glenn & Eddie Tuttle
Punta Gorda, FL
Note: This photo does not show Mark Brenan.