I've had an Electric Lavac for 5 years (including a one year cruise with a
child) and have mixed opinions, though I'm mostly positive.

The Lavac has airtight seals on the seat and lid so that when the pump runs (a
Henderson, now Whale, Mk 5 modified with a motor) a vacuum pulls the waste out
and pushes it off to the holding tank. The vacuum will also pull some seawater
into the bowl. The vacuum gets released by a small hole in the intake line that
must be adjusted for the geometry of the system.

Pros:
There are no moving parts in the toilet itself.
The pump can be located in an easily accessible location.
If jammed, the pump can be stripped down, cleared, and put back together in
about 30 minutes.
If the seals are worn, or if it is otherwise unable to draw in seawater, water
can still be added manually, and it can still be flushed.
The pump can be set up as a bilge pump.
If everything works properly, little water gets used.

Cons:
If the vacuum does not release, a child (or guest) cannot lift the seat. Maybe
this year I can teach my daughter (soon to be 9) how to do it. Although the
vacuum should release in a minute or so, I've never been able to adjust to do
this consistently.
The seals can come loose and a guest won't figure it out.
While the pump can handle a lot, it can still get jammed. Care must still be
taken, as with any marine head.

The electric version has a few quirks. I'm not sure how well it would do in
continuous duty, so I would hesitate to rely on it as a bilge pump. However, it
would be good to have a manual Mk 5 as a backup.

The electric has an odd timer switch that can be adjusted for about 30 seconds.
I added a manual bottom so it can be run for 10 seconds for liquid waste. The
switch cost $60, and can break.

The flapper valve on the electric is different from the manual version - it has
to be weighted, probably because the electric starts slowly and is too gentle on
clogs. Using the manual version of the valve will result in daily clogs. Trust
me - that's how I know I can field strip it in under 30 minutes.

All in all, I would still recommend it unless you have small children or
frequent guests.



"Drumm Law" wrote in message
...
All right, now, I need the straight poop here! (Pun intended, of course)

Looking at marine heads, it looks to me like I should replace my current
"pumper" with either an electric SeaEra or an electric Lavac. I don't quite
understand how the Lavac works . . . but they are supposed to be "the most
trouble-free" available.

Any comments? Peggy, help!!!