Freesound Forums

Hi all,

I was wondering if anyone had any experience recording waves coming in using a hydrophone buried in the sand?

The problem I'm having at the moment is using a hydrophone on a 10 metre cable and ending up standing in the crashing waves. I'm obviously going to have to brave the sea in order to get the mic back, but I'd rather not have to stand in the freezing water for hours whilst recording! I'd also feel more comfortable if my recording equipment was further removed from the water!

Are there any waterproof lead extension possibilities??

On marine cable connectors I used to use "Self amalgamating tape" waterproofing. It is a stretchy synthetic rubber tape which, like its name suggests, amalgamates with itself when stretched and overlapped to form a continuous skin. Done right it can form a completely watertight "cocoon" over cable joints. A search on-line should find plenty of suppliers. I have sucesfully sealed Radio UNC, in-line 1/4 jacks and XLR connectors on yachts that with additional ty-wraps have lasted years in semi submerged salt water situations. It is easy to cut off again when you want to disconnect without harming the cable or connectors.

Wibby

Cheers, that sounds like very useful stuff! I'll have to get hold of some.

I second what strangely_gnarled wrote. Self amalg is good stuff, stretch slightly as you create the spiral over the joint and you should get a 100% waterproof joint.

Thanks Benboncan.

I have another suggestion, but this one is effectively permanent, i.e. it will last "forever", but can't be undone without cutting off the connectors.

Search for "Adhesive lined Heatshrink tubing". This is a tube of insulating material which will shrink when heated with a hot-air gun (or very hot hair dryer). You will need a diameter that is big enough to slip over the connectors and a length that gives about 30mm or 1 inch over each cable. When it is heated it will shrink to conform to the surface of the connectors and cable, however it will probably not shrink all the way down to the diameter of the cables, so the ends can be "pinched" while still hot and the internal glue will bond and form a permanent seal, albeit with little wings where it was pinched. This technique is used to form permanent seals to underground High Voltage cables by utility companies, and is as durable as the cables themselves. However, as I said, it can't easily be "undone" to separate the extension from the Hydrophone other than cutting off and replacing the connectors. If you use this stuff make sure you use high quality connectors, or preferably soldered joints, on the cables.

regards, Wibby.

Thanks for the self amalgamating tape suggestion. I got hold of some and it's been working brilliantly.

I've been fortunate enough to have a DolphinEar Pro hydrophone for a few weeks. I would love one myself, however it may be a little too expensive.

Has anyone experienced using Aquarian hydrophones?