Advice... Broken Cav Plate

Hey all,


Looking for a bit of advice.


I have a Southwind 655 which had a hydrofoil on the outboard when I bought it.  The reading I did sugests the hulls were prone to porpoising and hence a lot of people put hydrofoils on.  Anyway 6 years later and I just left it there as the boat's always handled well.

I noticed about a year ago that the cavitation plate had cracked right through, and basically broken off.  It was only held on by the hydrofoil bolt.  I had it welded up and it broke again within a few weeks.  I assume that the hydrfoil is probably putting a far amount of flex on the plate and the weld wasnt strong enough.   The attached picture shows what I mean (an example, not mine).

When climbing back in the boat after a dive on the weekend a boat went past smashing me with wake (good to see everyone keeping a distance with a dive flag up), and I grabed the hydrofoil to stop breaking my face on the boat and it broke off in my hand (had gone a bit brittle).


SO... Has anyone successfully had a cav plate  welded up before?  If I get it welded again, and scrap the hydrofoil, will it hold up?  The boat seemed to handle ok with half of a hydrofoil so Im willing to give it a crack without one at all.

Or should I replace the hydrofoil along with the chunk of my cav plate?


Or... someone's no doubt going to tell me to replace the lower leg.  :P





Image Upload: 

Faulkner Family's picture

Posts: 16321

Date Joined: 11/03/08

 i would try getting it

Mon, 2019-01-07 17:23

 i would try getting it welded again and give it a go without the fins on it. you wont know until you try.if it breaks off you could still get back in . if it fails you would be better getting the leg replaced. 


RUSS and SANDY. A family that fishes together stays together

Lavs's picture

Posts: 166

Date Joined: 30/04/12


Mon, 2019-01-07 22:45


pelagicyachts's picture

Posts: 1079

Date Joined: 23/02/11

either that or change hydro

Tue, 2019-01-08 07:19

either that or change hydro foils -
get one that has bolts further back (see link below)- these you drill and bolt yourself (by the looks of it) so you could actually attach without re-welding the broken cav plate potentially