Replacement Log and Depth Sounder

[robf]

Hi all

Has anyone had experience at replacing/installing a new log and depth sounder? I have an old flashing-type depth sounder with a repeater in the cockpit that has failed. The impellor-style mechanical log has given up too and I'm looking at the RayMarine ST40 bidata - depth and log combined with two through-hull transducers. Is there a best position for the transducers on a Top Hat that is not too hard to install? While GPS is used now for position and speed etc, it doesn't give information about current without knowing speed through the water as well.

Any experience or thoughts much appreciated!

Warmer weather sailing soon!

Rob
Isabella II, Pittwater

[Dolphin]

G'Day Rob,
for what its worth, i have the old ST50 Autohelm insts. The log is positioned just aft of the galley under the settee berth and the sounder is positioned fwd of the galley under the port side berth.
Greg.
Felicite.

[storm petrel]

Hi Rob,

I recently installed an in hull hummingbird depth sounder last year. You just epoxy the sender inside the hull so it is one less hole in the hull to worry about. I fixed the sender inside the hull at teh bottom of the cockpit locker. It just give the depth on a digital display and has an alarm to warn of shallow water. To date it has worked perfectly.

Cheers,
Mark
(Storm Petrel Mk11)

[robf]

Thanks Greg and Mark

The current depth sounder has the in-hull sender too, and seems to work well. It's the repeater for the sounder and the mechanical log itself that doesn't work. I'll investigate the hummingbird depth sounder and maybe keep the GPS out for the speed for the short term solution.

Great sailing,

Rob

[surrealbass]

hi, I would agree with mark on storm petrel, I have a sounder on my planked timber tophat and it is fitted the same way. The only thing to remember is there must be absolutely no air between the sounder puck and the water. trick is to put it in an area where there is solid glass and seat it in resin or even sika( probably the best option anyway- just clean up area, mask off around where you want it neatly with tape, squelch a good dob of sikaflex on the puck, push home, wipe around edge with the rubber glove you are wearing to leave a nice fillet remove tape- leave to cure job done!! to be safe hook up and test before the sika cures!!!!!). Dunno but the log is really one of the less useful nav aids on tophat given the distances and gps positions. you can actually get a good guess going if you play a game with the gps guessing speed against the reading across ground on the gps. leave that job until you are out for a scrub!

Chris
Joylee

[Tales]

Tales has a depth transducer in a 'pot' bonded inside the hull and filled with water.
The pot is made from a piece of polly plumbing pipe about 100mm diameter.It is cut off on a angle to suit the hull shape and has a screw on cap (with an O ring seal) into which the trasducer is fitted.

The log is through the hull in the small space as you step up from the main cabin to the front cabin. Because it is fitted to one side, I find a speed difference of 1 knot from Starboard to Port tack at around 5 knots but spot on if motoring (with the boat vertical).

A friend told me that he fitted a depth transducer on a bracket and just put a big blob of grease under it and it never moved in 5 years! I did think that method a bit rough though!
Cheers,
Tom