Old Thruhulls . . Need Advice

[otherthan]

one is an old knot meter, the other looks like a dept sunder?

should I reuse them or totally remouve and patch the holes?

I do need to optain a dept sunder, so why not buy a similar model and use this part? or is it better to have a hand held dept sunder?

[rebel heart]

I have a handheld for scuba diving. It's nice because you can kick out on the surface and see how deep the water is below you without submerging. Trying to use it on the boat is a little weird because (a) it has to be in the water or up against the hull and (b) normally when you need to know the depth you're in shallow waters and the last thing you want to be doing is screwing around with some handheld device and not keeping your eyes on the helm.

I think the Pardey's use a handheld depth sounder and it works great for them, so this might just be a personal problem on my side.

[tartansail]

My experience has been that modern depthsounders usually can't use the old transducers. However, it's worth a try if you can figure out make and model of what you have.

I have no experience of handheld depthsounders, but concur that, when you really want to know your depth, you don't have spare hands or attention to look at an instrument you're holding in the water.

If your hull is solid glass below the waterline, you can mount a new transducer inside the boat against the hull and get good results without putting a new hole in the boat. Find a spot away from the keel and turbulence from the prop. Sometimes you can find a transducer purpose built for inside mounting. If not, you can glass a short section of PVC pipe against the hull, fill with water or antifreeze and mount the transducer there.