You own property where vehicles sit on the water.  

Also @Selina Giarla , this is just for your consideration , I know one CU that has 10YARM "Movable" product that their ARM is always have spread of negative 50-75 bps compare to 30YFRM.Currently they have:10/10 40 Years APR 6.440% Payment per $1,000 $5.77 30YFRM 6.875%APR: 6.892%Payment per $1,000 $6.57

What cash-flow, if any, you plan to generate from this property.If you are short on cash and/or your rental projections will be tight, then the 7/1 ARM might make more sense.If you are good on cash and/or your rental projects show that you will be generating sufficient cash flow, then the 30-year fixed might be a better option.I have used both mortgage vehicles for my properties, dependent on my situation at the time.  

Personally, I would diversify those funds into a few different investment vehicles.

We own 2 11-year old vehicles and are achieving other goals quicker as a result.

If someone “needs” that deep for a vehicle or boat, I would do a 12 wide by 10 tall door way unit building.Next product is surface parking.  

I LOVE short sales as an investment vehicle. 

I obviously have not considered your specific fact pattern so I won't comment upon it, but care is generally warranted with these types of fabricated transactional vehicles.

I read the predatory lending moved to vehicle dealerships.

Since IRA is tax-deferred vehicle - you will not get the same benefit by buying rentals in your IRA.On the other hand if you have personal savings and start doing private lending - the interest income you generate would be taxed at your top marginal tax rate.Therefore, generally, it is better to buy rentals in your own name and invest in trust deeds with your retirement funds.