Sea Me

cagey

cagey

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Next question.
Whats everyones opinion, both technical and practical about Sea me radar thingy. I do a lot of solo sailing and wondered is it usefull or not,
thanks
keith
 
I've just bought one.

I havn't tried it yet but it says in the instructions that it only transmits when it recieves a radar recieved signal.
Why not transmit intermittently like a racon?
Also detects your own radar transmission so the bleep on being radar swept is irrelevant.
However, I will cat nap easier with it!
 
I have had one for two years - brilliant! It has been "tested" with other small boats radars and gives a fantastic echo, especially when painted by a higher power set. Much better than any passive reflector used on mates boats. One minor snag - the bracket which attaches it to your mast is not the strongest. I have replaced mine with a similar one in stainless steel. It has a very low power drain so can be left operating when on a long passage. Although it does not happen so much now, when we first started using it it was a novelty in the area. We received a lot of attention from customs cutters, patrol boats etc one of whom explained that they had come to see what was making the big echo but registering as a small plastic yacht. I recommend it although no connection other than pleased buyer.
 
I wasn't aware that Sea Me existed till I read your entry, but of course I'm not surprised that it does exist, living within this Big Bang explosion of technology. I've just Googled Sea Me(thanks to you) and apparently it is the answer to the singled handed sailor's prayers if he or she is prepared to turn in and leave it to Sea Me to waken them on the approach of another vessel or object. I've wondered about something like this for years and have come to the conclusion that the longer our single handed sailor has been seagoing, the less chance he or she would have of getting any sleep at all, for the innumerable reasons racing around in their heads why one shouldn't do it. But what a tempter!!
 
i seem to remember reading a test in one of the mags a while back. it was top by a long way if my memory serves me well?
all the passive ones were all but useless!!
 
I fitted one three years ago. It works well by delivering a solid return on a radar set rather than a larger return. Take care to mount it in accordance with the instructions or interference from your own radar can lessen or even deaden the effect. MBM did a reflector test last year (?) and it certainly out performed all the others by miles - every pun intended!

By the way, you need an amendment to your radio licence (one of Offcom's free of charge services) since it is a transmitter.
 
It is an X-band transponder. X-band is more accurate but shorter range, S-band is used for longer range, is less accurate but gives better penetration of rain and clutter. Big ships usually have both, but may not use X-band further offshore. X-band is the type commonly fitted to small boats.

I looked at one at the boat show but I wasn't impressed by the disinterested salesperson and the almost total lack of any discount available. I went along to buy a "goodie" for the boat, but couldn't justify spending £500 on something with only one switch and one flashing led /forums/images/graemlins/smile.gif . I may get one before the next time I go on a longer trip, though. Current consumption seemed reasonable, I suspect price is the main reason you don't see many around.
 
One query I had was that the Sea Me is a band-x device. I read somewhere that ships often use just band-y when "at sea" and turn on the band-x set when close to shore. If this is true, it would mean that the Sea Me is of less use (particularly "offshore") - however, I can't find anything to confirm it. I'd still want a decent radar reflector to go with the Sea Me just in case.

Anyone know for sure what the operating procedures are on a ship? Would both band-x and band-y radars be on at all times?

Edit: Ah, just read Dave_White's reply. I guess when I say "y-band" I mean "s-band" - and perhaps ships do turn x-band off when offshore...

Rick
 
I did a quick Google and found this, which is reasonably succinct. I suspect that when the X-band is switched on varies quite a bit, but the message is that either a Sea-Me or a passive radar reflector is not a lot of use in mid-ocean.


Marine radar comes in two flavors, X-band and S-band. Ships will typically carry both, while small vessels are limited to the smaller X-band units. X-band radar operates at a frequency of approximately 9.4 GHz (9400 MHz), with a wavelength of 3.2 cm, while S-band operates at approximately 3 GHz, with a longer wavelength of 10 cm. X-band radar offers greater resolution and detection of smaller targets, but is more susceptible to interference from rain and seas (sea clutter). S-band radar has longer range and less interference from rain and sea clutter, but has less sensitivity for small targets.

A ship will typically use her X-band unit near shore, due to its higher resolution and ability to detect smaller targets. In conversations with ship’s officers, nearly all indicated that in offshore waters they depend entirely on the S-band unit set to a 24-mile scale. The advantage of S-band in this situation is longer range, less interference from rain, and reduced interference from sea clutter (a factor of about 2½, or -4 dB).

This is not good news for radar reflectors, however, since performance falls off as the square of wavelength. This means that, at least in theory, a given reflector will have an S-band return of only one tenth (-10 dB) compared to its X-band performance. In a situation where the return from the sea state is the limiting factor, part of this loss is made up by reduced sea clutter, but the effective return will still be reduced to one fourth (-6 dB) compared to X-band.

source
 
I've been at sea for 27 years now and on all the ships I've been on we have kept both radars running all the time. When deep sea (away from land) we used to keep one radar on long range S band (10cm) and the X band (3cm) on a shorter range due to previously mentioned characteristics of the sets.
Even now I'm running back & forth accross the N.Sea we still use this principle.
Our aim is to pick all targets up at a reasonable range and this sea me does sound to be the ideal gizmo for plastic boats to be detected by a vessel equiped with radar.

I have always advised anyone planning to put to sea to purchase the best radar reflector they can afford and check that their nav lights are switched on and working. Wood and GRP boats are notoriously difficult to detect on radar. Anything that helps being seen on radar will contribute to improved safety at sea.

Please remember, that although most ships have a good height of eye and therefore greater distance to the horizon it does not mean that small boats will be easily detected visually. If there is any chop, and in particular white horses, then any small (in particular white) boat will be difficult to see visually. Yachts under power without sails up are very hard to see. If motor sailing accross a busy lane then alway hoist a sail, so much easier to see even at night.

If it wasn't for the relatively high cost, I like many others would have bought a "sea me" by now. for me it's a question of priorities, and my extra cash will be going towards a liferaft first then maybe a radar then .......?

Cheers homa
 
Re: Sea Me rickp

It's almost academic, whichever band the radar is using, it is absolutely no use unless a watchkeeper looks at the screen, understands it and does something with the information.

At sea this is unlikely, they rely upon the zone alarms and on 25 mile range even the SeaMe is unlikely to trigger an alarm.

You can however, rely upon self-reliance.
 
The 2 bands are x and s. The regs are changing for radar reflector response to include both these bands. When they change, thre Sea Me will have to comply.

However, one important point is please don't rely on a big ship seeing a small boat. There is plenty of evidence to show this is a true statement.
 
Re: It\'s how much????

That's what I thought. The price of the Sea Me has shot up over the last few years and IMHO it is now looking increasingly less attractive. Pity really, electronics usually go down in price these days. Maybe they are just milking it? /forums/images/graemlins/mad.gif
 
Ever heard of fine print?

Sure they list it at £500. But the listing says "easy to fit using a standard antenna mount (not Included)". Now check the price of the SeaMe bracket.....
 
Re: Ever heard of fine print?

[ QUOTE ]
Sure they list it at £500. But the listing says "easy to fit using a standard antenna mount (not Included)". Now check the price of the SeaMe bracket.....

[/ QUOTE ]

Missed that /forums/images/graemlins/blush.gif

Just skimmed it - somehow knew it was too good to be true
 
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