Originally Posted by hellosailor
I'd suggest that SpareAir, in this context, is just one of the many ways dive shops are using FUD to sell more gear and make more profit. There is absolutely no need for "reserve" air if you are working on a recreational sailboat, where you will simply never be more than ten feet below the surface.
If someone can't hold their head together and make a free ascent from ten feet, even on empty lungs, THEY SHOULDN'T BE THERE IN THE FIRST PLACE. Period.
Agree with this part, but some of the Brownies third lung systems are rated to a depth of 90ft. Personally I'd like some kind of redundancy at that depth. J-valve to pony, pony with reg, or spareair or a straw to suck the air out of your drysuit
. No need for a backup if the system is for changing zincs.
Of course, one DIY system that won't contaminate your lungs is the $10 system developed and used by Motessier. On page 167 of his book "sailing to the reefs" he details a system of upturned buckets, weights, lines and other bits. He was able to use this system (with his friend refilling the buckets of air, upturning them and sending them down to him with a weighted line. Simplicity itself.
Check it out free here on google books:
Sailing to the Reefs - Bernard Moitessier, Rene Hague - Google Books