Descaling the loop on marine chiller system?

There should not be any need to descale the Fresh water side. Salt water side obviously yes every couple of years

16 yrs.?? Absolutely drain and flush with fresh water, refill and add food grade glycol to specified % and bleed air at the highest handler. Not so sure about the descale though unless you have submersion elements for heat that will add rust over time but I'm interested to hear others opinions on this.

Speaking of the salt water side, I came across a company a couple weeks ago that produces proprietary stainless sea strainers in various sizes that have direct current chlorine generators built into the lid with a dosing controller that produces a constant small stream of Sodium Hypochlorite into the raw water being consumed by AC condensers and such. Another option other than a suppressed current anode / cathode arraignment for sea chests. I can see an application in a regular shell and tube configuration for a chlorinator but am curious about chlorine and modern plate coolers and the dozens of gaskets involved. Has anybody used a "clearline" system made by a company called ElectroSea? Looks to be quality equipment and it makes sense in theory but curious about real time results in the field.

Makes sense, My first thought looking at this system was all the pool maintenance trucks with see through beds from carrying chlorine but of course that's an exaggerated example. That's what peaked my curiosity for any end consumers as this system has won numerous awards from IBEX on down. I've read everything that I can find about releasing a miniscule amount of chlorine into the raw water stream but so far, no customer testimonial's.

I use Bromine tablets (not Chlorine) in a/c sea strainers. The chlorine is too harsh.

Yes, it wouldn't hurt to descale a 16 year old system on the freshwater side. It could have all kinds of sylicates that dropped out of the coolant. I haven't seen it on Chilled water a/c's but I had the heat exchangers dropped on a pair of 6v53's that were low hour (400) SMOH but 7 years old and the heat exchangers on the freshwater side were all blocked with nasty nasty stuff.